In Tenshō 3 (1575), the smoke of the Battle of Nagashino had not yet cleared, but Oda Nobunaga's fame had already spread across Japan like wildfire.
From east to west, north to south, everyone knew the name "Oda Nobunaga." He was no longer the ridiculed "Great Fool of Owari," nor just an ordinary daimyō ruling two or three provinces. Now Oda Nobunaga held Yamashiro, Ōmi, Wakasa, Ise, Mino, Owari, Echizen, Yamato, Kawachi, Izumi, Kii, Tajima, Tanba—thirteen provinces in all, stretching hundreds of miles from east to west, commanding hundreds of thousands of troops.
His domain extended from the capital region to the Sea of Japan, and from the Kii Peninsula to the mountains of Mino. A single letter from him could raise a family to power; a single command could level a castle to rubble. His corps of retainers included Shibata Katsuie, Niwa Nagahide, Akechi Mitsuhide, Kinoshita Hideyoshi, Sakuma Nobumori, Takigawa Kazumasu—each a great commander. His army had arquebusiers, cavalry, marines, engineers—every branch of service, well equipped, well trained, and highly disciplined.
Standing on the tenshu of Gifu Castle, Nobunaga looked down at the castle town below, bustling with commerce and crowded with people. In the distance, the waters of the Nagara River glittered in the sunlight, stretching north and west toward the invisible horizon.
But his gaze did not linger on the prosperous streets. It passed over the river, over the mountains, toward the far west—there lay Kyoto, the imperial court, the centre of the realm.
Gifu Castle, renamed by him after his defeat of Saitō Tatsunori, had witnessed his entire rise from an ordinary warlord to the hegemon of the realm. But now this castle was no longer sufficient.
It was not that Gifu was weak—built against a mountain, strong and well repaired, its defences were excellent. Nor was it lacking in grandeur—its tenshu soared into the clouds, white walls and black tiles shining in the sun. The problem was its location. It was not central enough.
Gifu lay in southern Mino, near Owari. For Nobunaga's early expansion, it had been a perfect strategic base. But now his power extended west into the capital region, north to the Sea of Japan, and south to the Kii Peninsula. Gifu, too far east, meant long communication lines and slow troop movements. He needed a place closer to Kyoto, better connected, to serve as a new headquarters.
He turned his gaze to Gamō District in Ōmi—Azuchi.
Azuchi, on the eastern shore of Lake Biwa, backed by mountains and facing the blue waters. Water routes led across Lake Biwa to Ōmi, Wakasa, and Echizen; land routes led east to Mino and Owari, west to Kyoto and Yamashiro. And Azuchi was only two days' journey from Kyoto—close enough to "hold the emperor and command the lords," yet far enough to avoid the constant bother of the court nobles.
In the first month of Tenshō 4 (1576), Nobunaga formally ordered the construction of an unprecedented great citadel at Azuchi.
Its name would be Azuchi Castle.
He entrusted the immense task to one of his most trusted generals—Niwa Nagahide.
Niwa Nagahide, nicknamed "Kome no Rokuzaemon" (the rice man), was steady, capable, and skilled in coordination—one of the few in the Oda clan with both military and administrative talents. His own castle, Sawayama, was the closest to Azuchi, with the best transport links. Nobunaga chose him not only for convenience but because he trusted Nagahide to handle the job perfectly.
Nagahide set to work immediately. He conscripted tens of thousands of craftsmen and labourers from his domain, brought in vast quantities of timber, stone, iron, and copper, and sent men to the mountains of Ōmi, Mino, and Owari to select the finest hinoki and sugi cypress, hauling them to Azuchi by oxcart.
The construction of Azuchi Castle was not Niwa Nagahide's task alone. Nobunaga ordered every general under his command—Shibata Katsuie, Kinoshita Hideyoshi, Akechi Mitsuhide, Sakuma Nobumori, all of them—to contribute men and materials.
Azuchi became a vast construction site.
From dawn to dusk, the sounds of hammering, sawing, and shouting echoed without cease. Craftsmen sweated, labourers carried loads on their shoulders. Huge stones, the smallest weighing several hundred pounds, the largest over a thousand pounds, were dragged from the mountains on rollers and ropes, then laid one by one to form the foundations. The challenge of moving and lifting them was immense.
Nagahide devised a method: place logs under the stones, then use oxen and horses to drag them, rolling forward. For uphill, add more oxen; for downhill, hold them back with ropes to prevent runaway. Crude but effective—stone by stone, they reached Azuchi.
After the foundations came the walls. Azuchi's walls were not ordinary rammed earth but stone masonry. Each stone was finely dressed, the gaps so tight that a knife blade could not be inserted. The angle of the walls was carefully calculated—steep enough to prevent climbing, yet solid enough to withstand earthquakes.
Multiple gate towers were connected by covered galleries, an ingenious design for both offensive and defensive purposes. Even if an enemy broke through the first gate, they would be trapped in the narrow space between towers, easy targets for the defenders.
The most striking feature was the seven storey tenshu.
The tenshu was the heart of Azuchi Castle, the symbol of Nobunaga's power and majesty. Rising seven storeys (with nine internal levels), each floor had a different function and decoration.
The ground floor contained granaries and arsenals, holding enough provisions and ammunition for years. The second floor housed guards, with several hundred elite warriors always quartered there. The third floor was a meeting hall, where Nobunaga met his retainers and received envoys. The fourth floor was a library, containing books and maps—though Nobunaga disliked reading, he collected many works on strategy, geography, and Western learning. The fifth floor was the living quarters, where he ate, rested, and met with his family. The sixth floor was a guest chamber for important visitors—imperial envoys, messengers from other daimyō. The seventh floor, the topmost, was Nobunaga's private space, accessible only to his most trusted men.
The exterior walls were painted with black lacquer, gleaming with a deep lustre in the sun. The windows were decorated with gold leaf, from a distance like twinkling stars. The roof was covered with dark green tiles that glimmered with a blue green light. At the highest point of the roof crouched a pair of golden shibi (ornamental finials), a style derived from Chinese "chiwei," said to ward off fire.
Azuchi Castle's tenshu was the tallest, largest, and most magnificent building in Japan at the time. It surpassed any palace in Kyoto, any temple in Nara. It was not just a castle—it was a monument towering over the land.
During construction, Nobunaga encountered a problem—Japanese craftsmen had never built anything so grand. They were familiar with traditional castles and temples, but the scale, structure, and decoration of Azuchi were far beyond their experience.
They did not know how to fire such huge, strong tiles, how to apply gold leaf to windows, or how to design the stepped back structure of seven diminishing storeys.
Nobunaga sent men to search for talent. He even looked overseas.
Though official relations with Ming China had ceased, private trade continued. Chinese and Korean merchants and artisans often crossed the sea to Japan, settling in ports like Hirado, Hakata, and Sakai. One such man was a Ming Chinese from Fujian who called himself "Ikkan."
Ikkan's original name is lost to history; after going overseas, he took the name Ikkan. He came to Hirado and made a living as a roof tile maker. He was exceptionally skilled—his tiles were hard, evenly coloured, and regular in shape, far superior to those made by native Japanese tile makers.
Nobunaga's retainers found him in Hirado and brought him to Azuchi.
Ikkan stood at the Azuchi construction site, looking up at the tenshu rising above him. He was silent for a long time. Then he nodded and said, "It can be done."
He was put in charge of firing the tiles for the tenshu roof. These were not ordinary tiles; they required special clay, special temperatures, and a special process. Ikkan brought his own techniques and materials from Fujian, built large kilns near Azuchi, and personally mixed the clay, tended the fires, and inspected every tile.
When the first batch came out of the kiln, he presented them to Nobunaga. Nobunaga picked up a tile, tapped it—it rang with a metallic sound—and then scratched its surface with a knife. The blade left only a faint white mark. Beside it, a Japanese made tile similarly scratched gave a deep groove and crumbled.
"Excellent tiles!" Nobunaga exclaimed. He turned to Ikkan and said, "From today, you are the general superintendent of tile making for Azuchi Castle."
Ikkan knelt, touched his head to the ground, and said in Japanese with a strong Fujian accent, "Thank you, my lord."
Ikkan was not the only foreigner at Azuchi. There were also stonemasons from Korea, carpenters from the Ryukyus, and cartographers from Portugal. They spoke their own languages, wore their own clothes, and contributed their own skills. Nobunaga treated them all equally—no discrimination, no rejection. If you had ability, he gave you food, wages, and respect.
Such tolerance was unheard of among the daimyō of the time.
The construction of Azuchi Castle took seven years.
Throughout those seven years, Nobunaga visited the site nearly every month. He climbed the scaffolding, checking every mortise and tenon; he crawled into the foundations, making sure each stone was level; he asked the workmen about their lives, raised their pay, gave them bonuses, and sometimes poured them sake.
Once, a workman crushed his fingers while moving a stone. Nobunaga went to see him personally, sent for the best doctor from Gifu Castle, and left a bag of coins, saying, "Heal well. When you are better, come back to work. My castle still needs your skill."
The workman knelt and wept.
Another time, a batch of Ikkan's tiles came out of the kiln with cracks and had to be discarded. According to custom, such a mistake could mean a fine at best, execution at worst. Ikkan knelt before Nobunaga, pale as death, expecting punishment.
Nobunaga picked up one of the cracked tiles, looked at it, and tossed it aside.
"Ikkan," he said, "men are not gods. They make mistakes. This batch is wasted, so fire another. Next time, be more careful."
Ikkan stared for a long time, then bowed his head three times.
In Tenshō 9 (1581), Azuchi Castle was finally completed.
That day, Nobunaga led all his generals and retainers in a grand dedication ceremony. He stood on the topmost floor of the tenshu, looking down at the castle town and the shimmering waters of Lake Biwa. He drew a deep breath.
Behind him, Shibata Katsuie, Niwa Nagahide, Akechi Mitsuhide, Kinoshita Hideyoshi, Takigawa Kazumasu, and others stood in a line. Their faces showed undisguised awe and reverence.
"My lord's castle," Hideyoshi whispered to Nagahide beside him, "is more magnificent than the Imperial Palace in Kyoto."
Nagahide nodded silently.
Nobunaga turned to face his retainers and suddenly smiled.
"From today," he said, his voice not loud but clear to every ear, "this shall be the centre of the realm."
Not long after Azuchi Castle was completed, a special visitor arrived.
He was Luís Fróis, a Portuguese Jesuit missionary who had lived in Japan for more than twenty years. He had seen countless castles and palaces, but when he first laid eyes on Azuchi, he was stunned speechless.
In a letter to the church in Europe, Fróis described Azuchi Castle in detail. He wrote:
"This castle is the most magnificent building ever constructed in Japan. Its tenshu, seven storeys high, has its outer walls painted with black lacquer and its windows decorated with gold leaf, shining in the sun like fire. The paintings inside depict Chinese sages, Japanese heroes, and even ships and animals from the West. The top floor is floored with pure gold, the walls are inlaid with mother of pearl, and the ceiling is painted with dragons. The beauty of this castle surpasses any European palace I have seen."
Fróis also noted that Nobunaga himself had a keen interest in Western culture. In the library of Azuchi Castle, Fróis saw several books brought from Europe and a world map. Nobunaga asked Fróis to explain the countries he had never heard of—Spain, Portugal, France, England, Rome…
"This is the Great Ming," Fróis said, pointing to China on the map. "Here is the sea, here is Japan. You see, Japan lies east of China, separated by the ocean."
Nobunaga stared at the map for a long time, then asked, "How much larger is the Great Ming than Japan?"
Fróis thought. "Perhaps… dozens of times larger."
Nobunaga was silent for a moment. Then he gave a short laugh, patted the map, stood up, and said no more.
Fróis did not know what Nobunaga was thinking. Perhaps he was contemplating the vastness of the world; perhaps he was considering even grander plans—ambitions he had never disclosed to anyone.
After Azuchi Castle was completed, Nobunaga ordered the high priest Genkō to write a book devoted to Azuchi, entitled the Azuchi Castle Record. It detailed the castle's scale, structure, decoration, and the labour and materials used. Later, this book became a precious source for studying Azuchi, giving future generations a vivid picture of the lost citadel.
After Azuchi Castle was finished, Nobunaga moved his headquarters from Gifu to Azuchi.
He did not forget Gifu. That castle had witnessed his entire rise from a provincial lord to the hegemon of the realm—it was where his fortunes began. He gave Gifu Castle to his legitimate son, Oda Nobutada.
Nobutada was then twenty four, handsome, skilled in both letters and war, and Nobunaga's most favoured son. Nobunaga entrusted him with the military and civil administration of Mino, Owari, and the home provinces, making him lord of Gifu Castle and commander of the eastern defences. It was both a test and a token of confidence.
Nobutada knelt before his father, received the seal of Gifu Castle, and bowed three times.
"Father, rest assured," Nobutada said. "I will not disappoint you."
Nobunaga looked at his son, a glint of satisfaction in his eye. He said nothing, just clapped Nobutada on the shoulder and turned away.
From Gifu to Azuchi—the centre of power had moved west. From then on, Azuchi Castle became the political, military, and cultural centre of Oda Nobunaga's realm, the "new Kyoto" in the minds of all Japan.
Nobunaga set up a full administrative system at Azuchi. He appointed Shibata Katsuie commander of the Hokuriku front, holding Echizen and Kaga; Kinoshita Hideyoshi commander of the Chūgoku front, charged with the western campaigns; Akechi Mitsuhide commander of the Ōmi Tanba front; Niwa Nagahide as the chief administrator of the Kinai region; and Takigawa Kazumasu commander of the Kantō front (soon to be dispatched east).
Each general received clear duties and domains. The Oda governing system evolved from an early "warlord confederation" toward a prototype of centralised rule. From the tenshu of Azuchi Castle, Nobunaga sat like a player before a giant chessboard, moving all the pieces at will.
From Azuchi, he could reach Kyoto in two days, Ōsaka Bay in three, Echizen in five, and the border of the Chūgoku region in seven. Excellent communications allowed his orders to reach every corner of his domain with the greatest speed.
In Tenshō 4 (1576), while Azuchi Castle was still under construction, an event of historic significance occurred—Ashikaga Yoshiaki died in exile at the age of sixty one.
Yoshiaki's death meant that the Ashikaga shōgunal line was extinct. The Muromachi shogunate—the regime founded by Ashikaga Takauji that had lasted more than 230 years—had officially come to an end.
Japan had no shōgun.
For centuries, though Japanese politics had been turbulent, the title "Seii Taishōgun" had always existed. Whether Ashikaga Takauji, Ashikaga Yoshimitsu, Ashikaga Yoshimasa, or Ashikaga Yoshiteru, the shōgun's seat was always occupied by an Ashikaga. Now, that seat was utterly empty.
Who would fill the power vacuum?
The answer was obvious.
Oda Nobunaga commanded the capital, controlled the court, had a vast army, and ruled thirteen provinces—soon to be fourteen or fifteen. In terms of strength, achievement, and prestige, no one could rival him. If he wished to become shōgun, he would seem to be ordained by heaven.
But Nobunaga did not rush to occupy the shōgun's seat.
He knew very well that while the title was honourable, it was also a double edged sword. To become shōgun would mean taking on the full responsibilities of the shogunate—reorganising its administration, managing relations with the court, dealing with the demands of all the daimyō. Moreover, he would become "public," bound by tedious rules and ceremonies.
Nobunaga did not like that.
He preferred to be a "crownless king"—possessing the real power of a shōgun without the empty title. He could disregard the shogunate's constraints, issue orders freely, and do as he pleased. People called him "Lord Nobunaga," which he liked; if they called him "Your Excellency the Shōgun," he would feel uncomfortable.
The court several times hinted that Nobunaga could become shōgun, kanpaku (imperial regent), or daijō daijin (grand minister of state), but he politely declined. He once said to a retainer, "Those empty titles mean nothing to me. What I want is the realm, not an office."
Yet he respected the court deeply.
The first thing Nobunaga did after Azuchi was completed was to restore the court's ceremonies and institutions. He repaired the damaged parts of the palace, supplied what was lacking, and revived the rituals and festivals that had been suspended for years. He also returned to the court, the emperor, and the nobles the lands that had been taken from them during the years of war, providing them with stable revenues.
Emperor Ōgimachi was profoundly grateful. He held a banquet for Nobunaga, poured him wine with his own hand, and gave him a precious garment. Nobunaga received it, bowed respectfully, and said, "Your Majesty, be at ease. Your servant will do his utmost to assist the court and bring peace under heaven."
The people of Kyoto also felt the change. Fewer robbers in the streets, more goods in the markets, and long absent laughter once again came from the teahouses and taverns. For more than a hundred years, since the Ōnin War, Kyoto had not enjoyed such stability.
An elderly man in Kyoto said, "I have lived over seventy years and have seen the soldiers of the Hosokawa, the Miyoshi, the Matsunaga, the Rokkaku… but never until now have I felt that Kyoto is truly at peace."
This flourishing scene spread not only to Kyoto but across all of Nobunaga's domains. Commerce prospered, agriculture flourished, and towns grew. Nobunaga had abolished barriers to promote free trade; he had unified weights and measures to facilitate commerce; he had repaired roads and bridges to improve transport; and he had encouraged foreign trade, buying arquebuses, gunpowder, lead, and copper from Portuguese and Dutch ships.
Oda Nobunaga's realm was steadily becoming a reality.
But he knew well that one great obstacle still lay in his path.
Not the Takeda—after Nagashino, though Katsuyori had fled back to Kai, the clan was crippled and could never again advance west.
Not the Uesugi—Uesugi Terutora (Kenshin), though fierce, was fully occupied in Echigo and had no strength to reach the capital region.
Not the Mōri—though powerful in the west, they were separated by the San'yō and San'in routes, and there was no immediate conflict.
The real obstacle was right under his nose—the Ikkō sect of Hongan ji.
Hongan ji and its followers were Nobunaga's most vexing enemy.
They did not have fixed castles like the Asakura and Azai, nor did they fight on open battlefields like the Takeda and Uesugi. Their followers were everywhere—farmers, merchants, artisans—spread through towns and villages. In ordinary times they were law abiding, but when Hongan ji issued an "Ofumi," they turned overnight into fanatical fighters, taking up arms to attack Oda territory.
Their organisation was as tight as a spider's web. Local "kō" (congregations) and "monjin" kept close contact through code words and secret letters. They had their own supply lines, their own intelligence network, their own command system. They did not rely on castles, so they could not be besieged; they did not depend on commanders, so decapitation strikes failed. Their faith was their weapon, their unity their fortress.
Nobunaga had launched several campaigns against Hongan ji, but with little success.
In Tenshō 4 (1576), he sent a naval force against Hongan ji's stronghold at Ōsaka, but the Mōri navy drove it off.
In Tenshō 5 (1577), he personally led an army against Hongan ji, but the followers fought desperately, and with the Mōri navy supplying them from the sea, the siege failed.
In Tenshō 6 (1578), he sent Kinoshita Hideyoshi against Hongan ji. Hideyoshi employed siege tactics—building earthen ramparts and digging moats around Ishiyama Hongan ji to cut off its land routes. But the sea supply route remained open, and Mōri ships continued to bring food and ammunition.
Nobunaga realised that to eliminate Hongan ji, he would have to cut off its outside support. The main outside supporter was the Mōri clan in the west.
He changed strategy—instead of attacking Hongan ji directly, he began to eliminate its allies one by one.
In Tenshō 6 (1578), Nobunaga sent Oda Nobutada to attack Harima Province, severing the land route between the Mōri and Hongan ji.
In Tenshō 7 (1579), he sent Kinoshita Hideyoshi to attack Tajima and Inaba, further compressing the Mōri. That year, Hideyoshi took Tottori Castle, breaking Mōri control over the San'in region.
The same year, Nobunaga had Niwa Nagahide and Akechi Mitsuhide attack Ikkō strongholds in Settsu and Kawachi. One after another, they were eliminated, and the followers lost their hiding places.
In Tenshō 8 (1580), Nobunaga sent his navy—now under Kuki Yoshitaka, who had built six massive ironclad ships and gained command of the sea—to blockade Hongan ji completely. The Mōri could no longer supply it.
Ishiyama Hongan ji was trapped and starving.
People died of hunger—the old, the children, women at prayer. Yet still no one surrendered.
Finally, Kennyo, the abbot of Hongan ji, could bear it no longer.
In the eighth month of Tenshō 8 (1580), Kennyo sued for peace.
Nobunaga's terms were harsh: Hongan ji would surrender Ishiyama, leave Ōsaka, and relocate elsewhere; it would henceforth not oppose the Oda nor interfere in politics.
Kennyo had no choice but to accept.
In the tenth month of that year, Kennyo and the remaining followers left Ishiyama Hongan ji for Kaidzuka in Izumi Province. Nobunaga set fire to Ishiyama Hongan ji, leaving it a ruin.
Later, Toyotomi Hideyoshi would build the famous Ōsaka Castle on those ruins. But that is another story.
The threat of Hongan ji was finally removed.
Nobunaga breathed a sigh of relief. The enemy that had plagued him for more than a decade, robbing him of sleep, was finally crossed off his schedule.
In Tenshō 6 (1578), Uesugi Terutora—known to the world as Uesugi Kenshin—died suddenly at Kasugayama Castle, aged forty nine.
Uesugi Kenshin was one of the most celebrated warriors of the Warring States, called the "Dragon of Echigo." He had fought four battles with Takeda Shingen at Kawanakajima, ending in draws. His military talent was considered the equal of Shingen's.
Had he lived, would he have marched west? Would he have fought Oda Nobunaga? No one knows.
But his death did remove a potentially great adversary.
After Kenshin's death, his adopted sons fought fiercely over the succession. The Uesugi clan declined rapidly in the strife and never again posed a threat to the Oda.
Takeda Shingen was gone; Uesugi Kenshin was gone. The two rivals most likely to contest the realm with Oda Nobunaga had both been taken by fate.
When Nobunaga heard of Kenshin's death at Azuchi Castle, he was meeting with his retainers. He was silent for a moment, then said, "Pity. Uesugi Kenshin."
No one knew whether he truly regretted it or merely spoke the words.
In Tenshō 9 (1581), Oda Nobunaga's power reached its zenith.
He controlled twenty nine provinces (or effectively sixteen, but his influence extended over all Japan), commanded several hundred thousand troops, and had a galaxy of talented generals and strategists. The court at Kyoto obeyed him; the daimyō of the land bowed to him. His Azuchi Castle was the greatest in the land; his policies were the foundation for the unification of the realm.
Oda Nobunaga, the "Great Fool" who had come from the Owari countryside, had become truly the "Master of the Realm."
But he could not stop.
Before his eyes still lay Shikoku, Kyūshū, the Kantō, and Ōu. Hongan ji had surrendered, but the Mōri remained in the west; the Chōsokabe in Shikoku; the Shimazu in Kyūshū; the Hōjō in the Kantō; the Date in Ōu. Some had already sent letters of submission, some were still waiting, some were still resisting.
Nobunaga still had much to do.
In the first month of Tenshō 10 (1582), Nobunaga held a grand New Year celebration at Azuchi Castle. Envoys came from daimyō all over the country, bringing rich gifts. The streets of Azuchi were decorated with lanterns and banners, crowded with people, and filled with festivities.
Nobunaga sat on the high floor of the tenshu, looking down at the scene. Beside him stood his son Nobutada, his retainers, and some guests from distant places.
"Nobutada," Nobunaga suddenly said.
"Father."
"Look at this realm," Nobunaga said, gesturing toward the distance. "From Azuchi Castle, how far can you see?"
Nobutada thought for a moment. "Perhaps twenty or thirty miles."
Nobunaga laughed. He stood up, went to the window, and pushed it open. The cold wind rushed in, snapping his robe.
"I see farther than you," Nobunaga said. "I see the whole realm—from Ōshū in the east to Kyūshū in the west."
He turned to his son, to his retainers, to the guests, and said, one word at a time—
"This year, I will ensure that there are no two masters under heaven."
"Long live the lord!" his retainers shouted in unison.
Nobunaga said nothing, only smiled slightly.
Outside the window, the sun was setting over Lake Biwa, turning the blue waters into a cloak of crimson and gold. In the distance, the mountains turned into dark silhouettes, stretching endlessly.
Oda Nobunaga turned and walked down from the tenshu.
He did not look back.