Wako Pirate Activities: 13th to 15th Century

The first recorded Wako activity occurred in 1223 when Kumju was raided. The first stage of these raids were minor in scale and occurred on sporadic intervals. Then the presence of Mongol troops in Korea put a temporary halt to the Wako activities. The Japanese resumed their pirate raids in 1350 with the waning of Mongol power. It was during this second stage from 1350 to 1392 that the Wako pirate activities were at their peak. These raids changed from mere acts of thievery to full scale combat between the two nations.

The initial attempts by the Korean military to combat the Wako pirates ended in disaster. In 1351, troops were placed aboard ships to fight the pirates. However, the military commanders did not engage the Japanese. Instead, they withdrew when the pirate ships were spotted or avoided closing in to fight. By this time, the Wako pirates had complete maritime supremacy in the Korean waters.

The Wako raids began to have devastating impact on Korea during the reign of King Kongmin (1351-1374). Main reason was the Wako raids were seriously depleting the royal court's tax rice which were shipped by waterways from the southern provinces. Thus, Kaesong, where the aristocratic ruling class was concentrated, faced imminent economic collapse. To protect the tax rice ships, the Koreans even hired six Chinese ship captains, but they were soundly defeated by the Japanese in 1358. In 1364, the king picked veteran troops from the northern frontier and placed them on a fleet of eighty ships. Soon, the fleet proceeded to Cholla Province to escort the tax rice ships. The fleet commander, despite a warning he received of an ambush, fell into a classic trap. Two Japanese ships feigned retreat. The Korean fleet gave chase, only to become surrounded and defeated. The Koreans lost sixty ships in that battle.

U Hyon-bo, a court admonishing officer, in 1373 admonished the king eloquently in his memorial. Excerpts as translated by Benjamin Hazard in his Ph. D. dissertation is as follows:

Critics have said that, because the [Japanese] pirates are good sailors, we should not meet them in naval warfare. If we build ships, this would double the burden on the people. This is not so. Pirates cannot be attacked from land. That condition is very clear. Moreover, in the driving off of pirates and preventing violence, our basic desire is on behalf of the people. Can critics think of minor distress of the people and give great grief to the country? Now, along the Tong and So River defenses are placed. When the pirates come sailing on the sea at will, our army stands on the shore and can do nothing more than look on with folded arms, even with a million picked troops. When it is a matter of water, what can they do? We ought to build ships, carefully equipped and armed [author's emphasis], and following the currents in long columns block their principle routes.

Starting in that same year, 1373, the Koreans finally seemed serious about combating the Wako and began to build up the Korean Navy. Ch'oe Yong, a leading army general, began to solicit for new warships. He wanted to increase the navy by 2000 warships and put all of the Korean military on them to fight against the Wako pirates. In October 1373, a demonstration was held for the King on the newly constructed warships with their fire arrows and fire tubes. However, no further progress with the naval armaments was made until 1377 when Ch'oe Mu-son gave his famous firepower demonstration of his new cannons.

In 1380, the cannon is finally used in naval combat against the Wako on the Kum River. The ensuing riverine engagement turned out to be victorious for the Koreans. One, the Japanese were taken completely by surprise by the use of the cannons on the ships. Second, many of the ships were burned by the fire arrows spewed out by the cannons.

Kobukson

The invention of the kobukson has often been attributed to Admiral Yi. His biography states he "invented" it, but it is more likely Admiral Yi took an existing design and modified it for his own special use. One reason is the term "kobukson" can be found in Korean annals early as 1414 when King T'aejong inspected this new type of war vessel. Given the surge in naval development from 1377 to combat the Wako raids, it is not surprising to find the Koreans experimenting with warships. Also in 1389, Yi Song-gye had assumed control of Korea and immediately took the offensive by attacking the pirates at their lair in Tsushima. This was led by Park Wi with over one hundred ships. Later, ex-King T'aejong, after he had officially stepped down from the throne, initiated his own punitive attack on Tshushima in 1419 . This was led by Yi Chong-mu with 227 ships.

The aggressiveness shown by King T'aejong toward sea-fighting makes it appear the kobukson was designed as an attack ship. Certainly by the time Admiral Yi modified it with new advanced cannons and iron spikes on the roof, it became an offensive weapon. In certain aspects, Admiral Yi used the kobukson as if it was the sea version of the ancient chariot. Sun Tzu's The Art of War makes frequent reference to the chariot and how to employ it in battle. Admiral Yi as a student of military classics must have realized the similarities, because he uses the kobukson as his main attack weapon in the Imjin War.

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