Hideyoshi failed to defeat the Chinese and Korean armies on the Korean Peninsula and the war ended only after his death in 1598. In the hope of founding a new dynasty, Hideyoshi had asked his most trusted subordinates to pledge loyalty to his infant son Toyotomi Hideyori. Despite this, almost immediately after Hideyoshi's death, war broke out between Hideyori's allies and those loyal to Tokugawa Ieyasu, a "daimyō" and a former ally of Hideyoshi. Tokugawa Ieyasu won a decisive victory at the Battle of Sekigahara in 1600, ushering in 268 uninterrupted years of rule by the Tokugawa clan. The Edo period was characterized by relative peace and stability under the tight control of the Tokugawa shogunate, which ruled from the eastern city of Edo (modern Tokyo). In 1603, Emperor Go-Yōzei declared Tokugawa Ieyasu "shōgun", and Ieyasu abdicated two years later to groom his son as the second "shōgun" of what became a long dynasty. Nevertheless, it took time for the Tokugawas to consolidate their rule. In 1609, the "shōgun" gave the "daimyō" of Satsuma Domain permission to invade the Ryukyu Kingdom for perceived insults towards the shogunate; the Satsuma victory began 266 years of Ryukyu's dual subordination to Satsuma and China. Ieyasu led the Siege of Osaka that ended with the destruction of the Toyotomi clan in 1615. Soon after the shogunate promulgated the Laws for the Military Houses, which imposed tighter controls on the "daimyōs", and the alternate attendance system, which required each "daimyō" to spend every other year in Edo. Even so, the "daimyōs" continued to maintain a significant degree of autonomy in their domains. The central government of the shogunate in Edo, which quickly became the most populous city in the world, took counsel from a group of senior advisors known as "rōjū" and employed samurai as bureaucrats. The Emperor in Kyoto was funded lavishly by the government but was allowed no political power. The Tokugawa shogunate went to great lengths to suppress social unrest. Harsh penalties, including crucifixion, beheading, and death by boiling, were decreed for even the most minor offenses, though criminals of high social class were often given the option of "seppuku" ("self-disembowelment"), an ancient form of suicide that now became ritualized.