Oda Nobunaga (織田 信長 June 23, 1534 – June 21, 1582) was a powerful daimyō (feudal lord) of Japan in the late 16th century who attempted to unify Japan during the late Sengoku period, and successfully gained control over most of Honshu. Nobunaga is regarded as one of three unifiers of Japan along with his retainers Toyotomi Hideyoshi and Tokugawa Ieyasu. During his later life, Nobunaga was widely known for most brutal suppression of determined opponents, eliminating those who by principle refused to cooperate or yield to his demands. His reign was noted for innovative military tactics, fostering free trade, and encouraging the start of the Momoyama historical art period. He was killed when his retainer Akechi Mitsuhide rebelled against him at Honnō-ji.

The goal of national unification and a return to the comparative political stability of the earlier Muromachi period was widely shared by the multitude of autonomous daimyōs during the Sengoku period. Oda Nobunaga was the first for whom this goal seemed attainable. Nobunaga had gained control over most of Honshu (see map below) before his death during the 1582 Honnō-ji incident, a coup attempt executed by Nobunaga's vassal, Akechi Mitsuhide. Nobunaga was betrayed by his own retainers who set the Honno-Ji temple on fire; then, instead of burning in flames, Oda Nobunaga had committed seppuku to escape the flames. The motivation behind Mitsuhide's betrayal was never revealed to anyone who survived the incident, and has been a subject of debate and conjecture ever since the incident.[1]

Following the incident, Mitsuhide declared himself master over Nobunaga's domains, but was quickly defeated by Toyotomi Hideyoshi, who regained control of and greatly expanded the Oda holdings. Nobunaga's successful subjugation of much of Honshu enabled the later successes of his allies Hideyoshi and Tokugawa Ieyasu toward the goal of national unification by subjugating local daimyōs under a hereditary shogunate, which was ultimately accomplished in 1603 when Ieyasu was granted the title of shōgun by Emperor Go-Yōzei following the successful Sekigahara Campaign of 1600. The nature of the succession of power through the three daimyōs is reflected in a well-known Japanese idiom:

"Nobunaga pounds the national rice cake, Hideyoshi kneads it, and in the end, Leyasu sits down and eats it.