Toyotomi Hideyori (豊臣 秀頼 Toyotomi Hideyori), 1593 - June 5, 1615, was the son and designated successor of Toyotomi Hideyoshi, the general who first united all of Japan. His mother, Lady Yodo, was the niece of Oda Nobunaga.
When Hideyoshi died in 1598, the regents he had appointed to rule in Hideyori's place began jockeying amongst themselves for power. Tokugawa Ieyasu seized control in 1600, after his victory over the others at the Battle of Sekigahara. Hideyori married the seven year old granddaughter of Ieyasu, Senhime, to ensure his loyalty towards the Tokugawa clan. However Ieyasu continued to view the young Hideyori as a potential threat, and attacked Hideyori in the Siege of Osaka in winter 1614. The attack failed, but Hideyori was induced to sign a truce and dismantle the defenses of his stronghold Osaka Castle.
In April 1615, Ieyasu received word that Toyotomi Hideyori was gathering even more troops than in the previous November, and that he was trying to stop the filling of the moat. Toyotomi forces (often called the Western Army) began to attack contingents of the Shogun's forces (the Eastern Army) near Osaka. On June 5 1615. As Toyotomi's forces began to lose the battle, smaller force led directly by Hideyori sallied forth from Osaka Castle too late, and was chased right back into the castle by the advancing enemies; there was no time to set up a proper defense of the castle, and it was soon ablaze, and being pummeled by artillery fire. Hideyori committed seppuku, and the final major uprising against Tokugawa rule for another 250 or so years was put to an end.