Nobunaga Flag

was a Japanese ''daimyō'' and one of the leading figures of the Sengoku period. He is regarded as the first "Great Unifier" of Japan.

Nobunaga was head of the very powerful Oda clan, and launched a war against other ''daimyō'' to unify Japan in the 1560s. Nobunaga emerged as the most powerful ''daimyō'', overthrowing the nominally ruling shogun Ashikaga Yoshiaki and dissolving the Ashikaga Shogunate in 1573. He conquered most of Honshu island by 1580, and defeated the ''Ikkō-ikki'' rebels in the 1580s. Nobunaga's rule was noted for innovative military tactics, fostering of free trade, reforms of Japan's civil government, and the start of the Momoyama historical art period, but also for the brutal suppression of those who refused to cooperate or yield to his demands. Nobunaga was killed in the Honnō-ji Incident in 1582, when his retainer Akechi Mitsuhide ambushed him in Kyoto and forced him to commit . Nobunaga was succeeded by Toyotomi Hideyoshi, who along with Tokugawa Ieyasu completed his war of unification shortly afterwards.

Nobunaga was an influential figure in Japanese history and is regarded as one of the three great unifiers of Japan, along with his retainers Toyotomi Hideyoshi and Tokugawa Ieyasu. Hideyoshi later united Japan in 1591, and invaded Korea a year later. However, he died in 1598, and Ieyasu took power after the Battle of Sekigahara in 1600, becoming shogun in 1603, and ending the Sengoku period.

Early life (1534–1551)

Oda Nobunaga was born on 23 June 1534 in Nagoya, Owari Province, and was the second son of Oda Nobuhide, the head of the powerful Oda clan and a deputy (military governor), and his wife Dota Gozen.Jansen, Marius (2000). ''The Making of Modern Japan, '' p. 11. Nobunaga is said to have been born in Nagoya Castle, the future seat of the Owari Domain, although this is subject to debate. Nobunaga was given the childhood name of , and through his childhood and early teenage years became well-known for his bizarre behavior, receiving the name of . Nobunaga was a clear speaker with a strong presence about him, and was known to run around with other youths from the area, without any regard to his own rank in society. With the introduction of firearms into Japan he became known for his fondness for guns.

In 1549, Nobuhide made peace with Saitō Dōsan by arranging a political marriage between his son and heir Nobunaga, and Saitō Dōsan's daughter, Nōhime. Dōsan therefore became Nobunaga's father-in-law.

Unification of Owari (1551–1560)

Succession crisis

In 1551, Oda Nobuhide died unexpectedly. It has been said that Nobunaga acted outrageously during his funeral, throwing ceremonial incense at the altar. Although Nobunaga was Nobuhide's legitimate heir, a succession crisis occurred when some of the Oda clan opposed him. Nobunaga, collecting about 1,000 men, suppressed the hostile members of his family and their allies. However, Imagawa Yoshimoto sent army under the command of Imagawa Sessai laid siege to Anjō castle, where Oda Nobuhiro, the illegitimate son of Nobuhide and eldest brother of Nobunaga, was living. Nobuhiro was trapped, but was saved when Nobunaga handed over one of his hostages at Honshōji temple, nine-year-old Matsudaira Takechiyo – later known as Tokugawa Ieyasu – to make up for not lifting the siege of Anjō. Later on, Nobuhiro plotted against Nobunaga with the assistance of Saitō Yoshitatsu, but Nobunaga forgave Nobuhiro after the plot failed.

In early 1552, barely several months after his father's death, one of Oda's senior retainers, Yamaguchi Noritsugu and his son Yamaguchi Noriyoshi defected to Imagawa clan. In response, Nobunaga attacked Noritsugu, but was repelled by Noriyoshi at Battle of Akatsuka, he retreated and left contested lands in eastern Owari under Imagawa control.

Consolidation of clan leadership

In spring 1552, Nobuhide's younger brother, Oda Nobutomo, attacked Nobunaga domain with the support of Shiba Yoshimune, the official governor of Owari province. Nobunaga repelled it and burned the outskirts of Kiyosu castle.

In 1553, Hirate Masahide, a valuable mentor and retainer to Nobunaga, performed to startle Nobunaga into his obligations. In the meantime, Shiba Yoshimune informed Nobunaga of a plot of Nobutomo to assassinate him, and later, Oda Nobutomo had Yoshimune put to death. Nobunaga mobilized his forces to blockade Kiyosu castle, and waited for the opportunity to attack.

In 1554 Nobunaga defeated the powerful Imagawa clan, whose army had invaded eastern Owari Province, at the Battle of Muraki Castle. After recapturing eastern Owari, Nobunaga then turned his attention back to attacking Kiyosu castle, where he defeated and captured his uncle, Oda Nobutomo, and forced him to commit suicide.

In 1556, Nobunaga sent an army to Mino Province to aid his father-in-law, Saitō Dōsan, after Dōsan's son, Saitō Yoshitatsu, turned against him. The campaign failed, as Dōsan was killed in the Battle of Nagara-gawa, and Yoshitatsu became the new master of Mino. Later, Nobunaga defeated his main rival as head of the Oda clan, his younger brother Oda Nobuyuki, at the Battle of Ino. Nobuyuki survived the battle and began plotting a second rebellion.

Nobuyuki began his second rebellion in 1557, but was defeated and his Suemori Castle was destroyed by Nobunaga's retainer Ikeda Nobuteru.

In 1558, Nobunaga sent an army to protect Suzuki Shigeteru, lord of Terabe Castle, during the Siege of Terabe. Shigeteru had defected to Nobunaga's side from Imagawa Yoshimoto, a ''daimyō'' from Suruga Province, one of the most powerful men in the Tōkaidō region. In the meantime, Nobunaga defeated Oda Nobukata at the Battle of Ukino. Oda Nobuyuki started plotting again, but was denounced by Shibata Katsuie, one of his retainers, and killed on November 2, 1558.

By 1559, Nobunaga had captured and destroyed Iwakura Castle, eliminated all opposition within the Oda clan, and established his uncontested rule in Owari Province.

Rise to power (1560–1568)

Conflict with Imagawa

Imagawa Yoshimoto was a long-time opponent of Nobunaga's father, and had sought to expand his domain into Oda territory in Owari. In 1560, Imagawa Yoshimoto gathered an army of 25,000 men, Takeuchi, Rizō (1985). ''Nihonshi shōjiten'', p. 233. and marched toward the capital city of Kyoto, with the pretext of aiding the frail Ashikaga Shogunate. The Matsudaira clan also joined Yoshimoto's forces. The Imagawa forces quickly overran the border fortresses of Washizu, and Matsudaira forces led by Matsudaira Motoyasu took Marune Fortress. Against this, the Oda clan could rally an army of only 2,000 to 3,000 men. Some of his advisors suggested that he take refuge at Kiyosu Castle and wait out a siege by the Imagawa, but Nobunaga refused, stating that "only a strong offensive policy could make up for the superior numbers of the enemy", and calmly ordered a counterattack against Yoshimoto.

Battle of Okehazama

In June 1560, Nobunaga's scouts reported that Yoshimoto was resting at the narrow gorge of Dengaku-hazama, ideal for a surprise attack, and that the Imagawa army was celebrating their victories over the Washizu and Marune fortresses. While Yoshimoto viewed victory ahead, Nobunaga's forces marched to the Atsuta Shrine, a fortified temple overlooking the Imagawa camp. Later, Nobunaga moved to Zensho-ji fort, set up a decoy army there, marched rapidly behind Yoshimoto's camp, and attacked after a terrific thunderstorm. Yoshimoto was killed by two Oda samurai. With his victory in this battle, Oda Nobunaga gained greatly in prestige, and many samurai and warlords pledged fealty to him.

This battle was the first time Nobunaga noticed the talents of the sandal-bearer Kinoshita Tōkichirō, who would eventually become Toyotomi Hideyoshi.

Alliance with Matsudaira (later Tokugawa) and Takeda

Rapidly weakening in the wake of this battle, the Imagawa clan no longer exerted control over the Matsudaira clan. In 1561, an alliance was forged between Oda Nobunaga and Matsudaira Motoyasu (who would become Tokugawa Ieyasu), despite the decades-old hostility between the two clans. Nobunaga also formed an alliance with Takeda Shingen through the marriage of his daughter to Shingen's son.

Mino campaign

In 1561, Saitō Yoshitatsu, an enemy of the Oda clan, died suddenly of illness and was succeeded by his son, Saitō Tatsuoki. However, Tatsuoki was young and much less effective as a ruler and military strategist compared to his father and grandfather. Taking advantage of this situation, Nobunaga moved his base to Komaki Castle and started his campaign in Mino Province, defeating Tatsuoki in both the Battle of Moribeand the Battle of Jushijo in June that same year.

By convincing Saitō retainers to abandon their incompetent and foolish master, Nobunaga significantly weakened the Saitō clan. In 1564, Oda Nobunaga dispatched his retainer, Kinoshita Tōkichirō, to bribe many of the warlords in the Mino area to support the Oda clan. In 1566, Nobunaga charged Kinoshita with building Sunomata Castle on the bank of the Sai River opposite Saitō territory, to serve as a staging point for the Oda forces, and to intimidate, surprise, and demoralize the enemy.

In 1567, the Mino Triumvirate (西美濃三人衆, Nishi-Mino Sanninshū) was commanded by three samurai generals serving the Saitō clan: Inaba Ittetsu, Andō Michitari, and Ujiie Bokuzen. The triumvirate agreed to change sides and join the forces of Oda Nobunaga. Their combined forces mounted a victorious final attack at the Siege of Inabayama Castle. After taking possession of the castle, Nobunaga changed the name of both Inabayama Castle and the surrounding town to Gifu. Nobunaga derived the term ''Gifu'' from the legendary Mount Qi (岐山 ''Qi'' in Standard Chinese) in China, on which the Zhou dynasty is fabled to have started. Nobunaga revealed his ambition to conquer the whole of Japan, and also started using a new personal seal that read Tenka Fubu (天下布武),Gifu Castle
. Oumi-castle.net. Retrieved December 5, 2007. literally "All under heaven, spreading military force", or more idiomatically, " All the world by force of arms". Remains of Nobunaga's residence in Gifu can be found today in Gifu Park.

Ise campaign, Omi campaign and march to Kyoto

Following Nobunaga's conquest of Mino Province in 1567, Nobunaga sent Takigawa Kazumasu on a campaign comprising two invasions of Ise Province in 1567 and 1568 that defeated numerous families of Ise. Also in an effort to cement an alliance between Nobunaga and rival warlord Azai Nagamasa from Omi Province, Nobunaga arranged for Oichi, his sister, to marry Nagamasa. Nobunaga desired peaceful relations with the Azai clan because of their strategic position in between the Oda clan's land and the capital, Kyoto.

In 1568, Ashikaga Yoshiaki and Akechi Mitsuhide, as Yoshiaki's bodyguard, went to Gifu to ask Nobunaga to start a campaign toward Kyoto. Yoshiaki was the brother of the murdered 13th shogun of the Ashikaga Shogunate, Yoshiteru, who had been killed by the Miyoshi ''sanninshu'' (three chiefs of the Miyoshi clan, Miyoshi Nagayuki, Miyoshi Masayasu and Iwanari Tomomichi). Yoshiaki wanted revenge against the killers who had already set up a puppet shogun, Ashikaga Yoshihide. Nobunaga agreed to install Yoshiaki as the new shogun, and grasping the opportunity to enter Kyoto, started his campaign. An obstacle in southern Ōmi Province was the Rokkaku clan,_led_by_Rokkaku_Yoshikata.html" ;"title="DF 53 of 80/nowiki>">DF 53 ...