Siege of Odawara (1590)

Tenshō 18, seventh month, fifth day

On the fifth day of the seventh month of Tenshō 18 — 4 August 1590 in the proleptic Gregorian calendar — the Hōjō leader Ujinao and his brother Ujifusa left Odawara and surrendered at the camp of Takigawa Katsutoshi, one of Toyotomi Hideyoshi's commanders.

The submission followed negotiations that had begun in early June and continued after envoys entered Odawara Castle to meet him. Odawara City's account estimates about 180,000 besiegers against roughly 50,000 defenders.

The 'one-night castle' took months

By late June nearly every important Hōjō supporting castle except Oshi had fallen, and Odawara — whose outer earthwork enclosure ran more than nine kilometres around castle and town — was encircled by land and sea.

Ishigakiyama, remembered as the castle raised overnight, was not. Odawara's museum says construction began in early April, masonry was finished by mid-May, and Hideyoshi moved his headquarters there on the twenty-seventh day of the sixth month — weeks after peace talks had already started.

The castle changes hands, and the bill comes due

Ujinao's surrender ended organized Hōjō resistance, but the transfer of the castle was a separate process. Tokugawa Ieyasu began receiving it the following day, and the formal handover is dated to the ninth day of the month.

Hideyoshi assigned responsibility for the war to Ujinao's father Ujimasa, to Ujiteru, and to two other Hōjō leaders; Ujimasa and Ujiteru were later ordered to commit seppuku.

Ujinao himself was spared and later sent to Mount Kōya.