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, however, 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).