The Japanese double-agent plot

As Yi won battle after battle, Hideyoshi and his commanders became anxious as they neared Busan. Yi constantly attacked and delayed supply ships bringing food, weapons, and reinforcements to the Japanese. At one point, the entire invasion was halted just before attacking Pyongyang when supplies and troops failed to reach the First and Second Divisions.

Hideyoshi soon adjusted. At Busan, the Japanese warships were reinforced and some cannons added to larger ships. The fleet clustered beneath the harbor's defenses of heavy shore-mounted cannons that were acquired from the armory. But, above all, the Japanese knew that, for a successful invasion of Joseon, Yi had to be eliminated. Not a single Japanese ship would be safe for as long as he was commanding the sea.

Taking advantage of the many internal court rivalries of the Joseon Dynasty, the Japanese devised a plan. A Japanese double agent named Yoshira (要時羅) was sent to the Joseon general Kim Gyeong-seo (김경서; 金景瑞; 1564–1624), and convinced the general that he would spy on the Japanese. Yoshira played this role until Kim began believing anything he would say.

One day, he told General Kim Gyeong-seo that the Japanese general Katō Kiyomasa would be coming on a certain date with a great fleet for another attack on the south shores and insisted that Admiral Yi be sent to lay an ambush. General Kim agreed and sent the message to Field Marshal Gwon Yul (권율; 權慄; 1537–1599), Commander-in-Chief (도원수; 導元帥) of the Joseon military, who, in turn, sent the message to King Seonjo. King Seonjo, who was desperate for victories to loosen the Japanese grip on his kingdom, gave permission for the attack. When General Kim gave Admiral Yi his orders, the admiral refused to carry them out, for he knew that the location given by the spy was studded with sunken rocks and was thus extremely dangerous. Admiral Yi also refused because he did not trust the words of spies.

When General Kim informed the king of Admiral Yi's refusal, the admiral's enemies at court quickly insisted on his replacement by General Won Gyun, former commander of the Gyeongsang Province Western Fleet & Commander of the Jeolla Province Ground Forces. They advised that Admiral Yi be arrested.

As a result, in 1597, Yi was relieved of command, placed under arrest, and taken to Seoul in chains to be imprisoned and tortured. Yi was tortured almost to the point of death by using simple torture tactics such as whipping, flogging, burning, the cudgel, or even the classic technique of leg breaking torture. King Seonjo wanted to have Yi killed, but the admiral's supporters at court, chiefly the minister Jeong Tak (정탁; 鄭琢; 1526–1605), convinced the king to spare him due to his past service record. The prime minister, Yu Seong-ryong, who was Yi's childhood friend and his main supporter, remained silent during this deadly hour. Spared the death penalty, Admiral Yi was again demoted to the rank of a common infantry soldier under General Gwon Yul. This penalty was worse than death for Joseon generals at that time, since they lived by honor. However, Yi responded to this humiliation as a most obedient subject, quietly going about his work as if his rank and orders were appropriate. Despite his low rank, many officers treated him with respect, since they knew that the admiral did nothing wrong. Yi would stay under General Gwon Yul's command for a short while until Won Gyun's death at the Battle of Chilchonryang, which would lead to his reinstatement.

• Outline of Yi Sun-Shin (1545-1598)
  

  HISTORIC PEOPLE

  Yi Sun-Shin (1545-1598)

  Yi Sun-Shin was a Korean naval commander, famed for his victories against the Japanese navy during the Imjin war in the Joseon Dynasty, and is well-respected for his exemplary conduct on and off the battlefield not only by Koreans, but by Japanese admirals as well. Military historians have placed General Yi Sun-Shin on par with Admiral Horatio Nelson as arguably the greatest naval commander in history for his undefeated record against seemingly insurmountable odds despite no background in naval training.

  Early Life: Yi was born in Geoncheon-dong Street (건천동; 乾川洞), Hanseong (then capital, present-day Inhyeon-dong, Jung-gu District, Seoul) but spent his adolescence and early adulthood period before passing the military examination in Asan where his mother's relatives lived and where now a shrine to him stands.

  Japanese invasions of Korea (1592–1598): Yi is remembered for his numerous victories fighting the Japanese during the Japanese invasions of Korea (1592–1598). Among his twenty-three victories, the Battle of Myeongnyang and the Battle of Hansan Island are the most famous battles.

  Turtle Ships: One of Yi's greatest accomplishments was resurrecting and improving the turtle ship (거북선; 龜船). With his creative mind and the support of his subordinates, Yi was able to devise the geobukseon, or Turtle Ship.

  Japanese double-agent plot: A Japanese double agent named Yoshira was sent to the Joseon general Kim Gyeong-seo, and convinced the general that he would spy on the Japanese. Yoshira played this role until Kim began believing anything he would say.

  Joseon defeat at Chilchonryang and reinstatement of Admiral Yi: With Yi stripped of influence and negotiations breaking down in 1596, Hideyoshi again ordered an attack on Joseon. The second Japanese invasion landed in the first month of 1597 with a force of 140,000 men transported on 1000 ships.

  Battle of Myeongnyang: After careful study of potential battlefields, in October 1597 Admiral Yi lured the Japanese fleet into the Myeongnyang Strait, by sending a fast warship near the Japanese naval base and luring the Japanese fleet out of anchorage.

  Final battle and Admiral Yi's death: The battle began at two o'clock in the early morning of December 16, 1598. Like Admiral Yi's previous battles, the Japanese were unable to respond effectively to the Korean's tactics.

  Reactions by Joseon government: Admiral Yi repeatedly defeated the Japanese invasion force in battle, while preserving the lives of his soldiers and respecting their families. Yi was supported by the people of Joseon not only for his victories, but his kindness and gratitude towards those affected by the hardships of war.

  Legacy: Today, Admiral Yi is considered one of Korea's greatest heroes of all time. Koreans look upon Yi as a man of courage, perseverance, strength, self-sacrifice, intellect, and loyalty to his country.

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This article uses material from the Wikipedia article "Yi Sun-Shin", which is released under the Creative Commons Attribution-Share-Alike License 3.0.