How Admiral Yi saved Korea

'Who saved Korea from Japanese domination in the 1590's? Yi Sun-Sin.

I am listening to Professor Bullet's lectures on world history, and he notes that although most history books lament the loss of life in the 30 year war in Europe, few know about Japans war against korea (whose ultimate aim was to take over China) at the same time: that essentially destroyed Korea:

The total military and civilian casualty as estimated by the late 19th century historian, Geo H. Jones, is 1 million,^[8] and the total combat casualty ranges around 250,000...

most were starvation or disease (a lot of arable land was destroyed) but they also included brutality against civilians.

Japanese troops committed crimes against civilians in battles and killed indiscriminately, including farm animals.

The Korean army was outmatched, but their Navy, whose experience in fighting pirates was first rate, essentially stopped the conquest.

The Korean navy played a crucial part in the second invasion, as in the first. The Japanese advances were halted due to the lack of reinforcements and supplies as the naval victories of the Korean navy prevented the Japanese from accessing the south-western side of the Korean peninsula.^[165] Also, during the second invasion, China sent a large number of Chinese ships to aid the Koreans. This made the Korean navy an even bigger threat to the Japanese, since they had to fight a larger enemy fleet.

Japan eventually conquered Korea in 1910 and tried to take over China, (Wikipedia lists this as Japan's 35-year imperialist expansion (29 August 1910 to 15 August 1945). Another result was that Japan's Hideyoshi closed them country to foreigners and stopped the upward mobility of the peasants by confiscating their swords and forbidding them to become samurai.

So but one wonders if history would have been different if Admiral Yi hadn't been there 300 years earlier.

Yet who in the west, have ever heard of him?

Hint: The Geeks.

Yi (in his turtle ship) and his turtle ships appear in the game Age of Empires II: The Conquerors. However, for the purpose of balance, the turtle ships are wrong in two areas of the game: they are slow (in reality they were quite fast) and they can only fire the cannon out of the dragon's mouth/bow (the turtle ships actually fired broadsides and used the front mostly as a sulfur smoke blower and ram).

Yi also appears in the RTS game Empires: Dawn of the Modern World where he and his ship, the turtle boat, are playable characters. Yi's character is only playable in the campaign devoted to his plight in the Imjin war