The rifts within the Oda clan did not heal with the victory at Kiyosu Castle. Instead, they ran like an underground river, surging violently below the surface, waiting only for a breach to erupt.
In the spring of Tenbun 22 (1553), ill news came from Furuno Castle. Oda Nobumitsu—that uncle who had rendered great service in the Battle of Kiyosu—had been assassinated in his own castle by his retainers.
The cause was simple enough. Nobumitsu was brave, but he ruled his men with excessive harshness. He governed his troops with cruel laws, resorting easily to caning, confiscating stipends on the slightest displeasure, and even cutting down his own retainers. His men had long harboured resentment but dared not speak. That day, Nobumitsu was feasting several close attendants in the castle. Halfway through the wine, for some reason, Nobumitsu suddenly slammed the table and cursed, then drew his sword to strike a servant. The servant, frozen with terror, fled through the door, and Nobumitsu chased him, sword in hand. In the chaos, several samurai who had long planned the deed took advantage of Nobumitsu's distraction, stabbed him from behind with a spear, and then cut him down with several slashes. Oda Nobumitsu died on the spot.
By the time word reached Nobunaga, Furuno Castle was already leaderless and in turmoil. Nobunaga rode there that night, pacified the remnants, executed the rebellious samurai, and arranged Nobumitsu's funeral. Nobumitsu's death was a considerable blow to Nobunaga—this uncle had been not only a brave warrior but also fiercely loyal, a key pillar supporting Nobunaga's foothold in Owari. With that pillar broken, Nobunaga had to find another man to govern Furuno Castle.
After much thought, Nobunaga fixed his eyes on Hayashi Tōkatsu.
Hayashi Tōkatsu, also known as Hayashi Sadoken, was an old retainer of the Oda, having served both Nobuhide and Nobunaga. He was around fifty, steady and capable, and enjoyed considerable prestige within the clan. Nobunaga deemed him sufficiently experienced and able, and promoted him to lord of Furuno Castle, entrusting him with this strategic stronghold.
Whether Nobunaga did this out of trust or with some deeper intention, no one could say. But later events proved that this move was most unusual.
After receiving his appointment, Hayashi Tōkatsu appeared outwardly respectful and governed Furuno Castle competently. But in his heart, he harboured other thoughts.
Like many old retainers, he had always disapproved of Nobunaga's ways. Nobunaga's arrogant, headstrong nature in his eyes was "a sign of impending ruin." And Nobuyuki—that refined, courteous, gentle second son—was his ideal lord. Hayashi Tōkatsu secretly corresponded with Shibata Katsuie and others, plotting to depose Nobunaga one day and install Nobuyuki. Shibata Katsuie was also a fierce Oda warrior, immensely strong, wielding a great spear, invincible on the battlefield, but like Hayashi, he was dissatisfied with Nobunaga's conduct.
How much of this Nobunaga knew is uncertain. But one day, he did something that took everyone completely by surprise.
It was an ordinary spring afternoon. Hayashi Tōkatsu was handling official business in his residence at Furuno Castle when he suddenly heard hurried footsteps outside, followed by the panicked announcement of his attendant: "L-Lord! The lord is here!"
Hayashi Tōkatsu started. "Which lord?"
"Lord Oda Kazusuke! He is already at the gate!"
Kazusuke was Nobunaga's court title at the time. Hayashi Tōkatsu sprang from his seat, his face drastically changing. Why would Nobunaga suddenly come to Furuno Castle? No prior notice, no warning, just arriving uninvited? A sense of foreboding welled up in his heart. Fumbling, he straightened his cap and robes and hurried out to greet him.
Nobunaga had already entered the courtyard. He wore no armour today, just an ordinary black hitatare, a sword at his waist, and only two or three attendants behind him. But his eyes—those eyes were like two drawn swords. A single glance at Hayashi Tōkatsu made the old retainer's back break out in a cold sweat.
"Sadoken," Nobunaga said casually as he strode into the hall, plopped himself into the seat of honour, and crossed his legs. "I was passing by Furuno Castle and thought I'd drop in to see you. What, not welcome?"
Hayashi Tōkatsu hurriedly prostrated himself, his forehead touching the cool tatami, his voice trembling slightly: "M-My Lord honours me with his presence! I am immeasurably honoured! How could I not welcome you?"
"Good." Nobunaga looked around, surveying Hayashi's residence, then glanced at the documents and account books spread on the table. Suddenly he laughed. "You've fixed this place up nicely. Better than my Kiyosu Castle."
Hayashi Tōkatsu was uncertain whether this was praise or blame, and repeatedly said, "I dare not, I dare not. My lord's Kiyosu Castle is truly magnificent; this humble dwelling is merely a shelter…"
Nobunaga grunted noncommittally, then abruptly changed the subject. "I hear you've been visiting Shibata Katsuie quite often lately?"
Hayashi Tōkatsu's heart gave a violent lurch, as if someone had punched him hard in the chest. He looked up and met Nobunaga's half-smiling eyes. There was something in that gaze—hard to describe, like a probe, or a warning. Hayashi quickly lowered his head and forced himself to remain calm. "I… I have indeed had dealings with Shibata-dono, but they were about military affairs, nothing else…"
"Oh." Nobunaga nodded, asked no further, and instead turned to other matters—how the annual tribute harvest had been, how the castle repairs were progressing, how the soldiers were training. Hayashi Tōkatsu answered each question cautiously, not daring to say a word more than necessary.
Nobunaga stayed about half an hour, then rose to leave. As he left, he patted Hayashi Tōkatsu on the shoulder and said a sentence full of meaning: "Sadoken, you are a capable minister. Work hard, and I will not treat you poorly."
With that, he mounted his horse and rode away.
Hayashi Tōkatsu knelt at the gate to see him off, not rising until Nobunaga's figure had disappeared at the end of the street. Only then did he realize that his undergarments were soaked through with cold sweat, clinging to his skin like ice. His hands trembled slightly, his legs were weak, he could barely stand.
"He knows…" Hayashi muttered to himself. "He knows for certain…"
He stumbled back to the hall, collapsed onto the tatami, and panted heavily. Thoughts chased one another through his mind: Was Nobunaga's sudden visit a coincidence? His mention of Shibata Katsuie—was that a hint? The light in those eyes was unmistakably the look of one who saw everything. The more Hayashi thought, the more terrified he became, as if he could see Nobunaga already marshalling his troops to seize him.
Fear coiled like a serpent in his heart, never leaving.
And so he made the most mistaken decision of his life—to strike first.
Less than two hours after Nobunaga left Furuno Castle, Hayashi Tōkatsu assembled his trusted men and deployed them through the night. On one hand, he sent word to Shibata Katsuie; on the other, he moved troops to swiftly cut off every road from Furuno Castle to Kiyosu Castle. The post road between Furuno and Atsuta was blocked, the ferry crossings outside Kiyosu Castle were sealed, and supplies of grain and fodder could not pass. Overnight, Kiyosu Castle became an isolated fortress.
At dawn, word reached Kiyosu Castle.
Inside the castle, uproar broke out. Some retainers cursed Hayashi Tōkatsu for his ingratitude, some worried about insufficient provisions in the castle, and others secretly watched which way the wind would blow. Hayashi Tōkatsu had operated within the Oda clan for many years and had deep connections; once he rebelled, at least a third of the domain followed him into turmoil.
When Oda Nobunaga heard the news, he simply laughed. "Ha!"
"That old fool," Nobunaga said, flicking his fingernails carelessly. "I only went to his house and drank a cup of tea, and he wets his pants in terror. Well, if he wants to fight, I'll fight him."
Nobunaga was born, it seemed, without the nerve for fear. The more critical the moment, the more excited and clear-headed he became. He swept his gaze over the retainers present and quickly issued orders: some were to remain and defend Kiyosu Castle against a possible assault; the rest would march out of the castle with him, cross the river, and strike directly at Furuno Castle.
Outside, autumn rain drizzled. The sky was grey, the rain fine but persistent, pattering against the blue bricks of the castle walls. Nobunaga donned his Nanban-dō gusoku armour, mounted his horse, and led the army out of the castle through the cold rain. The rain grew heavier, the roads muddy and difficult; horses' hooves slipped frequently, slowing the march considerably. When they reached the Odai River, the sight before them made many soldiers catch their breath—days of rain had swollen the river. What was normally a shallow stream barely knee-deep now churned with muddy waves, fast and treacherous, its width more than twice the usual.
One retainer stepped forward and advised, "My lord, the current is too strong. To cross hastily would be dangerous. Better to wait until tomorrow, when the rain stops and the waters recede…"
Before he finished, Nobunaga cut him off with a curse: "Wait until tomorrow? By tomorrow that old man Hayashi Tōkatsu will have blocked every road! Cross now! Cross now!"
He was the first to spur his horse into the river. In an instant, the water rose above the horse's belly, ice-cold, the fierce current battering the animal's legs. The horse neighed and staggered. Nobunaga, with one hand gripping the reins and the other raising his whip, shouted, "All of you, follow! Anyone who falls back dies!"
Seeing their lord already in the water, the soldiers hesitated no longer. Gritting their teeth, raising their weapons, clutching their saddles, they stepped into the river one by one. Some foot soldiers slipped and were carried several paces downstream, only to be grabbed by a quick-handed comrade. The arquebusiers held their matchlock guns high above their heads, terrified that the rain would soak their powder. The entire army advanced with difficulty through the muddy waves, hand in hand, forming a human chain, inching step by step toward the opposite bank.
Before long, Nobunaga's force had all crossed the Odai River. Though a few soldiers had been swept away, the main body was intact. On the far bank, Nobunaga counted his men, shook the water from his helmet, and laughed uproariously. "It's just a river! What's there to fear? Send the order: the whole army marches straight to Furuno Castle! Let that old bastard Hayashi Tōkatsu try any more tricks now!"
Inside Furuno Castle, Hayashi Tōkatsu had been waiting for news that Nobunaga had been blocked by the Odai River. Instead, not only had Nobunaga crossed, but he was advancing with terrifying speed. Hayashi hastily mustered his troops, joined forces with Shibata Katsuie, and deployed in formation outside the castle.
The two armies faced each other on the plain outside Furuno Castle. The sky remained overcast, a fine rain falling like silk strands. The banners of both sides were soaked through, hanging heavy and limp, occasionally lifted by the wind to reveal a corner of their crests. Nobunaga's "Eiraku Tsūhō" banner stood high in the centre of his formation, wet but still conspicuous.
Shibata Katsuie sat his horse at the head of his formation, holding his great spear reversed, his figure as massive as an iron tower. He gazed at Nobunaga's lines across the field, his heart full of mixed feelings. He had plotted with Hayashi Tōkatsu for a long time, hoping to move gradually, but Hayashi had lost his nerve and rebelled at the first fright from Nobunaga. Now the arrow was on the string and must be loosed, yet in his heart he knew that victory was far from assured.
The battle began at noon. Nobunaga employed no complex tactics—he simply charged and battered. Leading the assault himself, he brandished his tachi and shouted fierce curses, routing the enemy and sending them fleeing in disarray. Nobunaga's troops were high in morale, while the allied forces of Hayashi and Shibata were already uneasy; added to that, Nobunaga had crossed the river so quickly that many had not even time to react before they were scattered. The battlefield shook with battle cries; rainwater, mud, and blood mingled underfoot, throwing up red splashes.
Just as the tide of battle was becoming clear, the appearance of one man completely reversed the situation.
Oda Nobuyuki—Nobunaga's younger brother—rode up to the front with a troop from Suemori Castle. Hayashi Tōkatsu and Shibata Katsuie were overjoyed to see Nobuyuki's banner, thinking he had come to reinforce them. But Nobuyuki, after dismounting, did not walk toward their lines. Instead, he raised both hands and walked toward Nobunaga's side.
"Elder brother!" Nobuyuki knelt in the rain, prostrating himself. "I was deceived by evil men and strayed from the righteous path. Now I come to confess my crime and submit myself to elder brother's judgment."
Nobunaga, on horseback, looked down at his younger brother kneeling in the mud. Rain dripped from the edge of his helmet, making his expression unreadable.
Hayashi Tōkatsu was thunderstruck. He stood frozen. He had never imagined that Nobuyuki, the very man he loyally wanted to enthrone, would defect at the most critical moment. He stood there, rainwater streaming over his graying hair and down his deeply wrinkled face—impossible to tell rain from tears. Shibata Katsuie, too, was stunned; his great spear clattered to the ground.
The game was lost.
Hayashi Tōkatsu sighed deeply, threw down his sword, and knelt in the rain. Shibata Katsuie was silent for a moment, then slowly knelt as well.
The fighting stopped abruptly.
Nobunaga rode up to Hayashi Tōkatsu and looked down at the old retainer from horseback. Hayashi Tōkatsu knelt on the ground, trembling all over, his forehead pressed into the muddy earth, not daring to lift his head.
"Sadoken," Nobunaga's voice came from above, neither high nor low, neither angry nor pleased, "I only went to your house and drank a cup of tea, and you rebelled. You have quite a small nerve, don't you?"
Hayashi Tōkatsu's voice was small as a mosquito's: "I… I deserve ten thousand deaths…"
Nobunaga dismounted, walked over to Hayashi Tōkatsu, and suddenly raised his foot, giving him a not-too-hard kick. "Get up. Stop kneeling. Take your men back and go about your business. Furuno Castle is still yours; guard it well. Next time, I'll hang your head from the castle gate."
Hayashi Tōkatsu shuddered and raised his head in disbelief. He had been certain Nobunaga would kill him, or at least strip him of his domain. Yet Nobunaga let him off so lightly, as if the fierce battle just fought had been nothing more than children playing at war.
"M-My Lord…" Hayashi's lips trembled, and to his surprise, his eyes reddened.
But Nobunaga had already turned away, waving his hand without looking back. "Everyone disperse. Back to the castle. I've been soaked in this rain all day; I'm going home for a bowl of hot soup."
Shibata Katsuie, kneeling nearby, had heard Nobunaga's disposal of Hayashi, and his heart churned. He had thought Nobunaga would seize the opportunity to purge all opponents, but Nobunaga not only spared Hayashi's life, he did not even order him to commit seppuku in apology—merely scolded him and let him go. Such magnanimity both surprised Shibata and stirred a faint sense of shame within him.
But matters in this world are rarely settled so simply.
Although Hayashi Tōkatsu's rebellion had been quelled, the fire in Nobuyuki's heart had not been extinguished after his surrender. Returning to Suemori Castle, the more he thought, the more resentful he felt. He had surrendered to Nobunaga only because circumstances forced him, not out of genuine submission. Deep in his heart, he had always believed that he should be the master of the Oda clan. The words of those old retainers echoed in his ears daily: "Nobunaga is a cruel tyrant; sooner or later he will destroy the Oda. Only you, Second Lord, are the one that everyone looks to."
In the autumn of Tenbun 23 (1554), Oda Nobuyuki secretly contacted his old supporters from Suemori Castle, planning to raise his forces again and fight his elder brother to the death. He summoned a few trusted retainers, closed the doors, and discussed how to launch a surprise attack on Kiyosu Castle while Nobunaga was unprepared.
The news soon reached Shibata Katsuie.
Shibata Katsuie hesitated for a long time. He had been one of Nobuyuki's supporters, his close friend, and had sincerely hoped that Nobuyuki would take Nobunaga's place. But the last defeat had taught him one thing: Nobunaga sat where he sat for a reason. That man possessed an irresistible force—not martial skill, not intelligence, but an indescribable spirit. He was like a red-hot iron ball; if you reached out to touch it, you would only be burnt to the bone.
Moreover, Nobunaga had spared his life last time. That debt of gratitude, he had to repay.
Shibata Katsuie ultimately made his decision. That night, he left Suemori Castle, raced to Kiyosu Castle on horseback, and asked to see Nobunaga. The two spoke for a long time in a private room; no one knows what they said. Only that when Shibata Katsuie left Kiyosu Castle, his face was grave and his steps hurried.
A few days later, a letter from Oda Nobunaga arrived at Suemori Castle. The tone of the letter was surprisingly cordial, saying roughly that the brothers had not seen each other for a long time and Nobunaga missed him greatly; he invited Nobuyuki to come to Kiyosu Castle the next day for a talk, to discuss the great affairs of Owari together.
Nobuyuki received the letter with some suspicion. He was plotting rebellion; going to Kiyosu Castle would be like delivering himself to the tiger's mouth. But Nobunaga's letter was so earnest that refusing would make him look guilty. After discussing it with his retainers, he decided to go—with a bodyguard of picked troops, so that if something happened, he could fight his way out.
The next day, Nobuyuki arrived at Kiyosu Castle with thirty guards. At the castle gate, retainers welcomed him warmly and led him through the long carriageway to the reception hall in the honmaru. Several of Nobunaga's senior retainers, such as Niwa Nagahide and Sakuma Nobumori, were already waiting in the hall; food and drink were set on the tables, and the atmosphere was most congenial.
Nobunaga came out from the inner chamber and laughingly invited Nobuyuki to sit. The two brothers sat face to face. After several rounds of wine, Nobunaga suddenly set down his cup and sighed.
"Nobuyuki," Nobunaga said, his voice not loud but clear throughout the hall, "we are brothers. I do not want to make things hard for you. But twice now you have tried to take my life. Tell me, what should I do?"
Nobuyuki's face changed drastically. He sprang to his feet and reached for his sword—but as soon as his hand touched the hilt, several samurai rushed out from left and right and pinned him down. Nobuyuki struggled a few times, then raised his head, his eyes full of anger and terror, staring fixedly at Nobunaga.
"Brother! You—!"
Nobunaga did not look at him. Instead, he raised his wine cup and spoke a single sentence to the retainers in the hall. The words were soft, but they pierced like a dagger into the hearts of all who heard them.
"Brothers are one's own limbs. But when those limbs try to cut off my head, how can I not cut them off?"
Before the echoes died, the retainers' long swords had already fallen.
Oda Nobuyuki, twenty-one years old, died in Kiyosu Castle.
When the news spread, Owari shook. Some said Nobunaga was cruel, killing even his own brother. Others said Nobunaga had acted in self-defence, forced to it. But many noticed a detail: after the incident, Shibata Katsuie was not only not punished, he was given important posts by Nobunaga. Shibata Katsuie, once a supporter of Nobuyuki, turned into one of Nobunaga's most capable and fierce generals.
It was Shibata Katsuie who had secretly informed Nobunaga of Nobuyuki's renewed plot to rebel.
Such was the Warring States. Today's ally, tomorrow's corpse beneath the sword; today's enemy, tomorrow's trusted retainer. The samurai code that had always proclaimed "loyalty unto death" was, before the reality of iron and blood, no more than a thin veil. Pull it aside, and beneath lay nothing but betrayal and scheming, lies and slaughter.
Nobuyuki was dead. Nobunaga's younger brother by the same mother, the one who had been most likely to replace him, vanished into the dust of history.
But it seemed that the Oda clan had not yet shed enough blood.
In Kōji 1 (1555), the year after Nobuyuki's death, another conspiracy came to light. This time, the instigator was Oda Nobunaga's elder half-brother—Oda Nobuhiro.
Nobuhiro was several years older than Nobunaga. Steady in temperament, he usually kept a low profile and was not particularly distinguished among the Oda. Yet in his heart, he too harboured discontent. When his father Nobuhide died, the family inheritance had fallen on Nobunaga, leaving him, the elder brother, as merely a retainer. During the struggle between Nobuyuki and Nobunaga, he had stood aside and watched without participating. But with Nobuyuki dead, Nobuhiro felt that his own chance had come.
Nobuhiro secretly made contact with the Saitō clan of Mino Province. The Saitō of Mino were a great power neighbouring Owari. Their lord, Saitō Yoshitatsu (though the narrative here may refer to the period of conflict between Saitō Dōsan and Yoshitatsu—in any case, the Saitō were enemies), was just then fretting over a pretext to expand into Owari. The two sides quickly reached an agreement and devised a deadly plot: The Saitō would make a show of a massive invasion of Oda territory; Nobunaga would surely lead his army out of Kiyosu Castle to meet them. Once Nobunaga's main force had left, Nobuhiro would raise troops from within and, attacking together with the Saitō from inside and outside, destroy Nobunaga in one stroke.
Everything was done in secret. Nobuhiro was careful, exchanging letters with the Saitō, each sealed with wax and delivered by his most trusted men. He believed his plan was flawless, that no matter how clever Nobunaga was, he could not detect it.
But he underestimated Nobunaga's intuition.
It was a winter morning. Nobunaga stood on the tenshu of Kiyosu Castle, gazing toward the northeastern horizon. A retainer reported: large numbers of Saitō banners and camps had been sighted on the border of Mino Province—signs of a large-scale invasion.
The retainers clamoured for battle, arguing that they must immediately send out troops to meet the enemy. The only question was how many men to send and who should command them.
Nobunaga, however, remained silent for a long time.
He looked at the intelligence, read it over several times, and then suddenly asked a strange question: "What has Nobuhiro been doing these past few days?"
The retainer was taken aback. "Lord Nobuhiro? He… he is in his domain, as usual."
"As usual?" Nobunaga gave a cold laugh. "The Saitō deploy such a great force on the border, and in his domain everything is 'as usual'? He hasn't even sent a report?"
The retainers looked at one another.
Nobunaga slapped the intelligence report onto the table and stood up. "Give the order: strengthen the castle's defences, clear the fields and stockpile supplies. No one is to venture out and fight without my command. All gates of Kiyosu Castle are to be shut tight; no one goes in or out without my authorisation."
"But my lord, if the Saitō attack…"
"If they attack, we have walls to stop them." Nobunaga's tone brooked no argument. "It is settled."
For several days, Nobunaga did not move, holding the castle tight. The Saitō army made a show of force on the border for a few days, but seeing that Nobunaga would not come out, gradually they withdrew. Saitō Yoshitatsu was not willing to waste his elite troops in a siege just for the sake of a man like Nobuhiro. Seeing that Nobunaga would not take the bait, he retreated decisively, without even a word to Nobuhiro.
Nobuhiro was dumbfounded.
He waited in his castle for news of a battle between the Saitō and Nobunaga. But what came instead was news of the Saitō's withdrawal. What terrified him even more was that Nobunaga did not relax his vigilance after the border crisis ended. Instead, he began secretly investigating Nobuhiro's recent contacts.
Nobuhiro knew that the game was nearly up.
Better to gamble everything than sit and wait for death. Nobuhiro threw off the mask, raised the banner of rebellion in his castle, assembled his troops, and prepared to launch a surprise attack on Kiyosu Castle. But his forces numbered only a few hundred, while Kiyosu Castle's garrison was in the thousands. No sooner had Nobuhiro's men left the castle than they were spotted by Nobunaga's patrols.
Nobunaga sent troops to surround Nobuhiro's castle and urged him to surrender. Nobuhiro tried to break out, but was driven back by a rain of arrows; most of his men were killed or wounded. Trapped in the honmaru of his castle, he looked around at the encircling enemy forces and knew that the cause was lost.
He sighed a long sigh, laid down his sword, and opened the castle gate.
Nobuhiro was bound and brought to Kiyosu Castle, where he knelt before Nobunaga. He expected death without question—he had conspired with foreign enemies, plotted to kill his lord, and then raised troops in rebellion. Any one of those crimes was punishable by death.
Nobunaga sat in the seat of honour, looked at him, and suddenly laughed.
"Elder brother, oh elder brother," Nobunaga said. "You truly are my good elder brother. Nobuyuki wanted to kill me, and you want to kill me too. Is my head so attractive to everyone?"
Nobuhiro lay prone on the ground, unable to stop trembling.
Nobunaga rose, walked over to Nobuhiro, and personally untied the ropes that bound him.
Nobuhiro raised his head in disbelief, his eyes wide, his lips quivering, unable to speak a word.
"Enough," Nobunaga said, clapping him on the shoulder. "You are my older brother. What good would it do me to kill you? Go back home and behave. Don't go sneaking around with outsiders again. Next time you break the rules, I really will be unforgiving."
Nobuhiro stared for a long time, then suddenly burst into tears, prostrating himself on the floor. The tears held shame, gratitude, the relief of a man who had survived a mortal peril—and also a genuine submission to this younger brother.
From that day on, Oda Nobuhiro was like a changed man. He became utterly loyal to Nobunaga, fighting fearlessly on the battlefield, performing repeated meritorious deeds, and never again harboured rebellious thoughts. To master great affairs, one must have great tolerance—Nobunaga's magnanimity was on full display in this moment. He knew when to strike and when to let go. When it was time to kill, he would not spare even his own brother; when it was time to forgive, he could pardon even a rebel. This was what set him apart from ordinary warriors.
The internal strife finally subsided. The opposition forces within the Oda clan were either dead, surrendered, or won over. Nobunaga had thoroughly secured his position as the head of the Oda family. But this was only the first step. His goal was never merely the Oda clan—it was the whole of Owari Province.
Owari's eight districts were divided into the four upper districts and the four lower districts. Through the Battle of Kiyosu, Nobunaga had brought most of the four lower districts, centred on Kiyosu Castle, under his control. But the four upper districts of Owari remained in the hands of another Oda branch—the clan of Oda Nobuyasu, based at Iwakura Castle.
Oda Nobuyasu, whose official title was Ise-no-kami, was the shugo-dai of Owari. Although he was of the same lineage as the Kiyosu Oda, he was of a different branch. He was advanced in years, his ambitions had faded, and his greatest concern in recent times was not warfare but the succession of his house.
Nobuyasu had two sons: the eldest, Oda Nobukata, and the second, Oda Nobuie. The eldest, Nobukata, was stubborn and headstrong, often at odds with his father. The second, Nobuie, was docile and clever, deeply loved by his father. Nobuyasu gradually began to consider setting aside the eldest in favour of the younger. He often told his retainers in private, "That boy Nobukata is violent and hot-tempered; he is not one to preserve the family. Nobuie, though young, is gentle, sensible, and well-versed in letters—he is the best choice to inherit the house."
When these words reached Nobukata's ears, he flew into a rage, smashing many things in his own quarters. "I am the eldest son! Why should Father pass the family to that snot-nosed brat?" He tearfully complained to the old retainers while secretly contacting those with grievances, preparing to strike first.
One night in Eiroku 1 (1558), Oda Nobukata staged a coup. He led his troops to surround his father Nobuyasu's residence, forced him to write an oath of retirement, and cede the position of chieftain to himself. Nobuyasu, old and weak, with few personal guards, could not resist. With bitterness in his heart, he affixed his blood seal to the oath. Nobukata, having obtained the oath, did not kill his father but drove him out of Iwakura Castle. Helpless, Nobuyasu took a few old servants and fled in a pitiful state to Mino Province, where he lived as a dependent of another house.
Nobukata took the seat of lord of Iwakura Castle as he had wished. But what he did not anticipate was that the seat was far less comfortable than he had imagined. Young and newly powerful, once he held authority, he threw himself into wine and women, indulging in banquets and pleasures all day long, leaving all military and political affairs to his retainers. Tax revenues went uncollected, castle defences fell into disrepair, and his retainers grumbled incessantly, but Nobukata paid no heed. When anyone remonstrated, he would curse them roundly, even throwing them into prison.
The power of Iwakura Castle steadily declined under Nobukata's hands.
When word reached Kiyosu Castle, Oda Nobunaga had been fretting over the lack of a pretext to move against the four upper districts. Hearing how the strife at Iwakura Castle had unfolded, he laughed uproariously. "Heaven helps me!"
Nobunaga did not act rashly. First, he won over a key figure—Oda Nobukiyo of Inuyama Castle. Inuyama Castle was located at the border between Owari and Mino, a position of great strategic importance. Though Oda Nobukiyo was of the same clan as Nobunaga, he also had marriage ties to the Iwakura Oda, and his stance had always been ambiguous. Nobunaga sent lavish gifts and a letter promising substantial rewards after the matter was accomplished. Weighing the pros and cons, Nobukiyo decided that following Nobunaga offered far better prospects than following that wine-soaked fool Nobukata, and agreed to send troops to help.
In the autumn of Eiroku 1, Oda Nobunaga and Oda Nobukiyo joined forces and marched on Iwakura Castle.
Iwakura Castle was a stronghold in the four upper districts, with high walls and thick ramparts, not easily taken. But after years of misrule under Nobukata, the garrison's morale was low and military preparedness had decayed. When Nobunaga's army arrived beneath the walls, only a few arrows came sparsely from the battlements. They were so badly aimed that they could not have hit a cat. Nobunaga, watching from horseback, could not help shaking his head. "With soldiers like this, they call themselves samurai?"
The siege proceeded far more smoothly than expected. Nobunaga ordered simultaneous attacks from all four sides. The arquebusiers fired volleys at the base of the walls, suppressing the archers on the ramparts. Oda Nobukiyo's troops swept around the flank, cutting off Iwakura Castle's line of retreat. Within three days, the outer castle had fallen.
Nobukata pulled back into the inner keep, determined to hold out. But where were his reinforcements? His father, whom he had driven away, was drinking bitter wine in Mino; the retainers he had offended wished him dead; the neighbouring daimyō were all watching the show. Inside the inner keep, Nobukata got dead drunk, alternately laughing and crying while hugging a wine jar, like a madman.
On the morning of the fourth day, Nobukata opened the castle gate. Barefoot, wearing a white kosode, carrying his own tachi in both hands, he walked out of the castle. He knelt before Nobunaga's horse and surrendered.
Nobunaga looked down at his former rival—a young man of about his own age, but his face was already bloated, his eye sockets deep, his whole body reeking of wine. Nobunaga gave a soft "hmph," did not take the sword, but turned to Niwa Nagahide beside him and said, "Take him away. Put him somewhere safe. Don't let him die, and don't let him drink any more."
Iwakura Castle fell into Nobunaga's hands. At this point, most of the four upper districts and four lower districts of Owari Province had been incorporated into Oda Nobunaga's territory. Although he had not yet gained complete control over the entire province, he had taken a solid and significant step forward—from Shobata Castle to Kiyosu Castle, from Kiyosu Castle to Iwakura Castle, he advanced step by step, each foot planted in blood and fire.
The enemies who had once stood in his path—Oda Hikogorō, Hayashi Tōkatsu, Shibata Katsuie, Oda Nobuyuki, Oda Nobuhiro, Oda Nobukata—either died, surrendered, or fled, one by one withdrawing from his path. But this was only the beginning of the Warring States. Ahead of him lay even stronger enemies: the great army of Imagawa Yoshimoto, rolling in from the Tōkaidō; the covetous Saitō of Mino; the realm far from pacified.
And that twenty-six-year-old Oda Nobunaga, standing on the tenshu of Kiyosu Castle, gazing in the direction of Kyoto with burning eyes—his journey had only just begun.