Burg Ōsaka
The last remaining threat to Ieyasu's rule was Toyotomi Hideyori, the son and rightful heir to Hideyoshi. He was now a young daimyo living in Osaka Castle. Many samurai who opposed Ieyasu rallied around Hideyori, claiming that he was the rightful ruler of Japan. Ieyasu found fault with the opening ceremony of a temple built by Hideyori; it was as if he prayed for Ieyasu's death and the ruin of the Tokugawa clan. Ieyasu ordered Hideyori to leave Osaka Castle, but those in the castle refused and summoned samurai to gather within the castle. Then in 1614, Tokugawa besieged the Osaka Castle against Hideyori.