As the continuation of Goryo military, the Joseon military maintained the primacy of the bow as its main stay weapon. Gungdo remained the most prestigious of all martial arts in Korea. Gungdo was the single most important testable event in gwageo, the national service exam used to select Army officers from 1392 to Gabo Reform in 1894 when gwageo system was terminated. During the Imjin War (1592–1598), Toyotomi Hideyoshi launched the conquest of China's Ming Dynasty by way of Korea. However, after two unsuccessful campaigns towards the allied forces of Korea and China and his death, his forces returned to Japan in 1598. but with heavy loss of men and cultural heritage. It was also during this war that the famous turtle ships (Geobukseon, 거북선) were used by Admiral Yi Sun-sin. These ships were covered with metal shields, much like the shell of a turtle, which could withstand the gun attacks of the Japanese. In 1593, Korea received help from China to win back Pyongyang. During one of the battles, the Koreans learned about a martial art manual titled Ji Xiao Xin Shu (紀效新書), written by the Chinese military strategist Qi Jiguang. King Seonjo (1567–1608) took a personal interest in the book, and ordered his court to study the book. This led to the creation of the Muyejebo (무예제보, Hanja: 武藝諸譜) in 1599 by Han Gyo, who had studied the use of several weapons with the Chinese army. Soon this book was revised in the Muyejebo Seokjib and in 1759, the book was revised and published at the Muyesinbo (Hangul: 무예신보, Hanja: 武藝新譜). During the Imjin war, three main weapons were identified by all sides as representative of their armies. The Japanese were known for their arquebus. The Ming Dynasty Chinese forces were known for their lance. Koreans were known for their Pyeonjeon used in conjunction with the Korean composite bow. During the war itself, Korea began adopting the Arquebus, eventually mastering it. Korean arquebusiers became so well known for their ability to kill tigers, which were rampant in Korea throughout its history until its final extermination in 1919, that Ming China requested the assistance of Korean arquebusiers against the rising Manchus in 1619. At the Battle of Sarhu, Korean order of battle was composed of 10,000 arquebusiers out of 13,000 total men. This event illustrates how Korea quickly adopted modern weaponry and discarded close quarter martial arts. Following the