Destruction of the Korean palace and its libraries in 1126 and the 1231 Mongol invasion and domination of Korea (Yuan dynasty, 1231-1356) eliminated Korea's prior literary history, and no first-hand accounts of the origins of "gwonbeop" are extant. In 1145, King Injong (r. 1112-1146) ordered Confucian scholar Kim Bu-sik to compile the "Samguk Sagi" ("History of the Three Kingdoms"). About a century later a Buddhist monk, Iryeon, compiled the "Samguk Yusa" ("Memorabilia of the Three Kingdoms"). According to both works, militancy between and among the three major states during the Three Kingdoms Period (37 BC–660 AD) resulted in each state developing an institution for training warriors. Although the term "gwonbeop " was not used, cadets of the Pyong Dang (educational institute) in Goguryeo learned punches and kicks ("ji leu ki beop"); cadets in Silla learned "chil kuk" (kicks) and "soo bak" (punches). In Baekje, open-handed fighting ("soo sool") was included in the training. Consolidation of the Korean peninsula under Silla in 668 enhanced its approach to hand-to-hand combat. Infrequent references to "soo bak" indicate that contests in unarmed combat, often with wagering by the audience, were held on holidays and other special occasions until the invasion of Korea by the Mongols (1231–1392).