Yoshihiro was feared as Oni-Shimazu ("Shimazu ogre") and his nickname spread across Korea and into China. In spite of the superiority of Japanese land forces, the two expeditions ultimately failed, though they did devastate the Korean peninsula. The causes of the failure included Korean naval superiority (which, led by Admiral Yi Sun-sin, harassed Japanese supply lines continuously throughout the wars, resulting in supply shortages on land), the commitment of sizable Ming forces to Korea, Korean guerrilla actions, wavering Japanese commitment to the campaigns as the wars dragged on, and the underestimation of resistance by Japanese commanders. In the first campaign of 1592, Korean defenses on land were caught unprepared, under-trained, and under-armed. They were rapidly overrun, with only a limited number of successfully resistant engagements against the more experienced and battle-hardened Japanese forces. During the second campaign in 1597, Korean and Ming forces proved far more resilient and with the support of continued Korean naval superiority, managed to limit Japanese gains to parts of southeastern Korea. The final death blow to the Japanese campaigns in Korea came with Hideyoshi's death in late 1598 and the recall of all Japanese forces in Korea by the Council of Five Elders, established by Hideyoshi to oversee the transition from his regency to that of his son Hideyori. Battle of Sekigahara Many samurai forces that were active throughout this period were not deployed to Korea; most importantly, the daimyōs Tokugawa Ieyasu carefully kept forces under his command out of the Korean campaigns, and other samurai commanders who were opposed to Hideyoshi's domination of Japan either mulled Hideyoshi's call to invade Korea or contributed a small token force. Most commanders who opposed or otherwise resisted or resented Hideyoshi ended up as part of the so-called Eastern Army, while commanders loyal to Hideyoshi and his son (a notable exception to this trend was Katō Kiyomasa, who deployed with Tokugawa and the Eastern Army) were largely committed to the Western Army; the two opposing sides (so named for the relative geographical locations of their respective commanders' domains) later clashed, most notably at the Battle of Sekigahara which was won by Tokugawa Ieyasu and the Eastern Forces, paving the way for the establishment of the Tokugawa shogunate. Social mobility was high, as the ancient regime collapsed and emerging samurai needed to maintain a large military and administrative organizations in their areas of influence. Most of the samurai families