"Imjinwaeran," also known as the Seven-Year War, refers to the Japanese invasions ordered by the Regent Toyotomi Hideyoshi, who re-unified Japan at the closing days of the Sengoku Jidai (the Japanese Warring States period when the country was divided among squabbling feudal lords), in the years from 1592 to 1598. Looking to expand his prestige as well as deal with the problem of an excessively large army with not enough spoils to distribute at the end of decades of bitter conflict in Japan, Toyotomi Hideyoshi sought to invade the gradually declining though still remarkably wealthy empire of Ming-chao (China under the Ming Dynasty).
As the Korean Peninsula was in a very close proximity to Japan, Toyotomi Hideyoshi made a request to the court of the Joseon Dynasty, the ruling dynasty of the Korean Peninsula, to allow Japanese troops passage through the Joseon Kingdom to Ming-chao. However, as Korea was a longtime ally of the Ming Dynasty, the Joseon court at first ignored Toyotomi Hideyoshi's ambassadors and later, King Seonjo of the Joseon refused. Toyotomi Hideyoshi commanded his forces to enter the Korean peninsula by force and thus began his campaign of expansionism despite reservations expressed by some of his own key advisors including Tokugawa Ieyasu (who would later betray Toyotomi Hideyoshi's hier, Hideyori, to establish the Tokugawa Shogunate).
The armies of Toyotomi Hideyoshi had two major advantages - advanced arquebus guns from the Portuguese and a well-equipped, battle-hardened, veteran army led by fierce generals who had served in the Sengoku Jidai.
The Koreans on the other hand were ill-prepared. Earlier, despite warning signs of the Japanese threat, and the scholar Yu Seong-ryong's calls for military reform and construction of fortifications, the Joseon court would not act. The Joseon Royal Army was no match for the hordes of veteran samurai and experienced extremely devastating losses in open confrontation with the Japanese forces. The Japanese committed wanton pillaging and slaughter, leaving much of the Joseon kingdom in smoldering ruins.
However, the Koreans were not totally helpless. Aside from assistance from the Wanli Emperor of Ming-chao, which came later in the Imjinwaeran, the Koreans had some brilliant admirals and generals. The Korean struggle for survival brought also the development of some of the most ingenious weapons ever created (including the famed Geobukson, the world's first cannon-armed ironclads, and the Hwacha rocket carts) at the time and a useage of guerilla tactics as well. Although the Japanese had many initial successes, pushing far into the heartland of the Joseon Kingdom, Korean forces and later Korean-Chinese allied forces, beat back the Japanese onslaught. And in 1598, the Japanese invasion was finally crushed.
Despite the Korean victory and the threat of early Japanese incursion of China, the war devastated the Korean peninsula. As a result of extremely heavy losses, the Joseon court turned inward and the period of the Joseon Dynasty's dynamic prosperity had been shattered, a legacy that would prompt Korea to remain the so-called "Hermit Kingdom" until the dynasty's eventual collapse under Japanese imperialism in 1910. The Joseon kingdom's age of technological innovation and economic and intellectual dynamism was disrupted severely and isolationism and conservatism prevailed.
The heavy costs of the war also emptied the already-diminished treasury of Ming-zhao; the Ming could no longer finance defenses against the Jurchens. The Jurchens, who renamed themselves the "Manchus," led their armies from their capital at Shenjing (now Shenyang) into the Ming-chao capital of Beijing after a major rebellion and total fiscal collapse in the Ming government prompted the suicide of the last official Ming Emperor. The Manchus established Da-Qing (the Empire of Great Qing) in 1644.
In Japan, the heavy losses also dwindled Toyotomi Hideyoshi's power. His own successor, Toyotomi Hideyori, was eventually ousted by Tokugawa Ieyasu, who established the Tokugawa Bakufu (shogunate) officially in 1603, only three years after he defeated his rivals and former allies in the battle of Sekigahara and merely five years after Toytomi Hideyoshi's collossal failure in Korea.
While the results of the Imjinwaeran inadvertently brought about the isolation and decline of Korea, the war had far-reaching consequences. It not only was a major catalyst in shaping the changes that would alter the political landscape of East Asia, but it also prevented Japan from gaining a foothold on the continental mainland from which it could pursue campaigns of expansionism into the rest of East Asia, maintaining a balance of power in the region for the next few centuries.
- Stephen Turnbull and Wayne Reynolds' The Fighting Ships of the Far East.
- Jacques Gernet, J.R. Foster, and Charles Hartman's A History of Chinese Civilization.
-Ki Baik Lee's A New History of Korea