Oda Nobunaga (1534-1582): The First Great Unifier of Japan

Oda Nobunaga was the Japanese warlord who began the unification of Japan after a century of civil war. Between his surprise victory at Okehazama in 1560 and his death in the Honnō-ji incident of 1582, he seized Kyoto, ended the Ashikaga shogunate and crushed rival lords and armed Buddhist movements. His innovations and his ruthlessness made him the first of Japan’s three great unifiers, followed by Toyotomi Hideyoshi and Tokugawa Ieyasu.

Background: Japan in the Sengoku period

By the mid-16th century the Ashikaga shoguns in Kyoto had lost almost all real authority. Since the Ōnin War of 1467-1477, Japan had been divided among regional warlords, the daimyo, who fought for land and survival. Historians call this the Sengoku, or “Warring States”, period.

Nobunaga was born in 1534 in Owari province, around modern Nagoya, the son of Oda Nobuhide, a minor but ambitious lord. As a youth he was known for eccentric behaviour and was nicknamed the “fool of Owari”. After his father’s death around 1551-1552 he fought relatives and rivals, and by 1559 he had brought most of Owari under his control.

The period also brought new technology. Firearms had arrived with the Portuguese at Tanegashima in 1543, and by the 1560s Japanese workshops were producing them in quantity. Nobunaga was among the warlords quickest to equip his troops with them.

Okehazama and the rise to power

In 1560 Imagawa Yoshimoto, one of the strongest daimyo in eastern Japan, invaded Owari with an army usually estimated at 25,000 men or more. On 12 June 1560 Nobunaga, with perhaps 2,000 to 3,000 troops, attacked Yoshimoto’s camp at Okehazama during a storm. Yoshimoto was killed and his army scattered.

The victory transformed Nobunaga’s position. In 1562 he made an alliance with Matsudaira Motoyasu, later known as Tokugawa Ieyasu, who had broken away from the Imagawa. The alliance secured Nobunaga’s eastern flank for the next twenty years.

Nobunaga’s early success owed much to his choice of followers. He promoted men for ability rather than birth, including Kinoshita Tōkichirō, the son of a foot soldier, who later took the name Toyotomi Hideyoshi. He also moved his headquarters as his territory grew, from Kiyosu to Komaki and, after conquering Mino, to Gifu, keeping his base close to the front and his retainers dependent on him rather than rooted in their own lands.

In 1567, after years of campaigning, he conquered the neighbouring province of Mino and its castle of Inabayama, renaming the town Gifu. Around this time he began using a seal with the motto “tenka fubu”, usually translated as “the realm under military rule”, signalling ambitions beyond his own provinces.

Into Kyoto and the end of the Ashikaga

In 1568 Nobunaga marched on Kyoto with Ashikaga Yoshiaki, a claimant to the shogunate, and installed him as shogun. For a time Nobunaga ruled through Yoshiaki, but the two soon clashed, and Yoshiaki encouraged other lords to oppose his patron.

A coalition formed against Nobunaga, including the Asakura of Echizen, the Azai of northern Ōmi, the Takeda of Kai and the Buddhist forces of the Hongan-ji. Nobunaga and Ieyasu defeated the Asakura and Azai at the Battle of Anegawa in 1570. In 1573, after the death of the powerful Takeda Shingen, Nobunaga drove Yoshiaki out of Kyoto, effectively ending the Ashikaga shogunate, and destroyed the Asakura and Azai.

Religion: Buddhist enemies and Jesuit guests

Some of Nobunaga’s most determined enemies were religious. The great monastery of Enryaku-ji on Mount Hiei, near Kyoto, had supported his enemies. In 1571 his forces burned its temples and killed large numbers of monks and residents; contemporary accounts speak of several thousand dead, although recent archaeology suggests that some of the destruction may have been exaggerated.

The Ikkō-ikki, leagues of followers of the True Pure Land school of Buddhism, controlled whole districts. Nobunaga’s campaigns against them were brutal. At Nagashima in 1574 his forces killed tens of thousands of people, with contemporary sources citing figures of around 20,000 in the final stage. The fortified Ishiyama Hongan-ji in Osaka resisted a siege from 1570 until 1580, when its leaders finally negotiated a withdrawal.

Nobunaga met Jesuit missionaries, notably the Portuguese priest Luís Fróis, whose writings are a key source for his character. He allowed them to preach in Kyoto and to open a seminary at Azuchi. Historians generally see his tolerance as partly political, given his struggle with Buddhist institutions and his interest in trade and European goods.

In 1581 the Jesuit visitor Alessandro Valignano came to Kyoto with an African attendant who entered Nobunaga’s service under the name Yasuke. Japanese and European sources record him, though many details of his life remain uncertain.

Nagashino, Azuchi and new methods

In 1575, at the Battle of Nagashino, Nobunaga and Ieyasu defeated Takeda Katsuyori, using large numbers of musketeers behind wooden palisades. The battle is often seen as a symbol of the new warfare, though historians now doubt later claims of perfectly drilled rotating volleys.

From 1576 Nobunaga built Azuchi Castle on the shore of Lake Biwa, completed in 1579. Its richly decorated tower keep, several storeys high, was designed to display his power and became a model for later Japanese castles. It was destroyed by fire shortly after his death in 1582.

Nobunaga also used economic tools. He promoted rakuichi rakuza, “free markets and open guilds”, which removed the privileges of guild monopolies in towns under his control, and he abolished many toll barriers on roads. He controlled the wealthy port city of Sakai, a centre of trade and gun production. In 1578 his navy defeated the Mōri fleet at Kizugawaguchi with large ships reportedly reinforced with iron plates.

Key people

• Oda Nobunaga (1534-1582): daimyo of Owari and the dominant power in central Japan from 1568.
• Toyotomi Hideyoshi (1537-1598): a commoner who rose to become one of Nobunaga’s leading generals and later his successor.
• Tokugawa Ieyasu (1543-1616): Nobunaga’s ally from 1562 and later founder of the Tokugawa shogunate.
• Ashikaga Yoshiaki (1537-1597): the last Ashikaga shogun, installed by Nobunaga in 1568 and expelled in 1573.
• Akechi Mitsuhide (c. 1528-1582): Nobunaga’s general who turned against him in 1582.

The Honnō-ji incident

By 1582 Nobunaga controlled a large part of central Honshu. In the spring of that year his forces destroyed the Takeda clan. He then prepared to support Hideyoshi, who was fighting the Mōri clan in western Japan.

Nobunaga stopped in Kyoto at the Honnō-ji temple with only a small guard. On the morning of 21 June 1582 Akechi Mitsuhide, ordered west with his army, turned instead on Kyoto and surrounded the temple. Nobunaga fought briefly and is believed to have died by suicide as the buildings burned; his body was never identified. His eldest son and heir, Oda Nobutada, was also killed in Kyoto the same day.

Mitsuhide’s motives remain one of the great puzzles of Japanese history. His rule lasted less than two weeks: Hideyoshi made peace with the Mōri, rushed back and defeated him at the Battle of Yamazaki on 2 July 1582. Mitsuhide was killed while fleeing.

Legacy

Nobunaga did not unify Japan, but he broke the old order. He removed the Ashikaga shogunate, weakened the military power of the great Buddhist institutions and showed how firearms, castles and control of commerce could be combined to build a large state. Toyotomi Hideyoshi completed military unification in 1590, and Tokugawa Ieyasu established the Tokugawa shogunate in 1603.

A well-known Japanese saying sums up the three unifiers: Nobunaga pounded the rice, Hideyoshi kneaded the dough, and Ieyasu ate the rice cake. Another popular verse contrasts their characters by imagining how each would deal with a cuckoo that will not sing, with Nobunaga simply killing it.

Nobunaga’s reputation is divided. He is admired as an innovator and a breaker of outdated institutions, and remembered for mass killings of civilians and monks. He is one of the most popular figures in Japanese novels, films, television dramas and video games.

Several popular beliefs about Nobunaga need qualification:

• Myth: Nobunaga invented the three-row rotating musket volley at Nagashino. This claim comes mainly from later accounts, and many historians doubt it was used in the precise way often described.
• Myth: Nobunaga was the first ruler of a united Japan. He controlled much of central Japan, but large regions remained outside his authority when he died.
• Myth: Nobunaga converted to Christianity. He protected missionaries but never became a Christian.

Timeline

• 1534: Oda Nobunaga is born in Owari province.
• 12 June 1560: Victory at Okehazama; Imagawa Yoshimoto is killed.
• 1562: Alliance with Tokugawa Ieyasu.
• 1567: Conquest of Mino; Inabayama is renamed Gifu.
• 1568: Nobunaga enters Kyoto and installs Ashikaga Yoshiaki as shogun.
• 1571: Destruction of Enryaku-ji on Mount Hiei.
• 1573: Yoshiaki is expelled; the Ashikaga shogunate ends.
• 1575: Victory over Takeda Katsuyori at Nagashino.
• 1576-1579: Construction of Azuchi Castle.
• 21 June 1582: Nobunaga dies in the Honnō-ji incident.

Why it matters

Oda Nobunaga turned the Sengoku wars from a struggle for survival into a drive for national power. By destroying the Ashikaga shogunate and the independent military power of religious institutions, and by pioneering new methods of war and government, he made the later unification of Japan possible.