Which 1582 incident at Honnō-ji ended Oda Nobunaga’s life?

The 1582 incident at Honnō-ji that ended Oda Nobunaga’s life was the Honnō-ji Incident.

Oda Nobunaga was staying at the Honnō-ji temple in Kyoto while preparing for further military campaigns. His subordinate general Akechi Mitsuhide unexpectedly turned his troops against him and surrounded the temple on 21 June 1582. Nobunaga, recognizing that defeat was unavoidable, is traditionally said to have committed suicide by seppuku after the temple was set on fire.

The incident transformed Japan’s struggle for unification. Nobunaga’s death created an immediate power vacuum, but Toyotomi Hideyoshi quickly defeated Akechi Mitsuhide at the Battle of Yamazaki and inherited much of Nobunaga’s political and military position. Honnō-ji was a temple rather than a castle, and Nobunaga was there with a relatively small personal force, making the surprise attack especially effective. The original temple was destroyed and later relocated elsewhere in Kyoto.