<P> In spite of the superiority of Japanese land forces, ultimately the two expeditions 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 sizeable 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). </P> <P> 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) would later clash, 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 . </P> <P> 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 that survived to the 19th century originated in this era, declaring themselves to be the blood of one of the four ancient noble clans: Minamoto, Taira, Fujiwara and Tachibana . In most cases, however, it is hard to prove these claims . </P> <P> During the Tokugawa shogunate, samurai increasingly became courtiers, bureaucrats, and administrators rather than warriors . With no warfare since the early 17th century, samurai gradually lost their military function during the Tokugawa era (also called the Edo period). By the end of the Tokugawa era, samurai were aristocratic bureaucrats for the daimyōs, with their daishō, the paired long and short swords of the samurai (cf . katana and wakizashi) becoming more of a symbolic emblem of power rather than a weapon used in daily life . They still had the legal right to cut down any commoner who did not show proper respect kiri - sute gomen (斬り 捨て 御免), but to what extent this right was used is unknown . When the central government forced daimyōs to cut the size of their armies, unemployed rōnin became a social problem . </P>

Which of the following is not included in a japanese samurai's traditional armor