This article covers Korea's military history from the Medieval era until 1700. The term Chosun is used because that was the name selected by the Korean and Chinese governments in 1388. It continued to be used into the 20th century with some maps of the Russo-Japanese War marking the Korean Peninsula as Chosun. This article discusses the Korean army and the surrounding areas that affected Korean military policy and events.

Sources

Much of the uniform information was obtained from a series of books written in Korean which contained not only accurate color drawings by modern artists plus numerous photos of statues and other contempory paintings. My sister-in-law, Woni Nelson, who is Korean, provided assistance in identifying the Generals and their nationality. Sources in English include:

The History of Korea by Han Woo-Keun offers a good historical overview.
A New History of Korea by Ki-baik Lee is especially informative and provides details about army organizations and other military history aspects.

Additional information can be found in the WRG's Army Lists for their Ancient rules and DBM system. These were written by Phil Barker.

The rise of the Yi Dynasty brought with it a focus on Confucian thought. As far as the effect on the military, its abhorrence of foreign trade resulted in policies of isolation and technological stagnation. While the isolationist policy allowed the army to focus on defensive strategies, it also caused the Korean Army to be surpassed in the important use of artillery and handguns. These gunpowder weapons reduced the formidability of previously impregnable Korean Fortresses. Even though the Japanese invasion of 1592 made the need to modernize obvious, the lack of native workers skilled in the manufacture of gunpowder and its weapons continued to hamper the modernization of the Korean Army.

During the Medieval era, the Koreans had military conflicts with various neighbors including Japan, nomadic tribes from Manchuria, the Ming Dynasty, and various warlord groups out of China. The political stability in those countries had a ripple effect on Chosun. As long as conditions were quiet in China, the border with Chosun remained calm. However when rebellions occurred, various refugees and rebel remnants crossed the border. These crossings were followed by Ming threats and demands for the refugees return. As a result, sometimes the Koreans would have to conduct campaigns against these bands and/or defend against Ming retaliatory raids.

On the other hand, stability in Japan meant that Japanese Shoguns would consider campaigns against China or Korea. As long as the Japanese were involved with factional fighting, only pirate raids would threaten Chosun. Likewise in Manchuria, as long as the nomadic tribes were divided, only light raiding activities affected the Korean border areas. Once the tribes were united, as under the Manchus, then serious invasions of Chosun could be expected.

For the most part, the extended dynastic rule of the Ming followed by the Manchus in China, Chosun experienced extended periods of relative peace marred occasionally by limited periods of military conflict and turmoil. The period after 1650 contained little military activity and this calm lasted well into the 1800s.

Chosun: The Isolationists of East Asia

Introduction
Military Organization and Notes
The Neighbors of Chosun Korea
Uniforms of the Yi Dynasty Era
Chronology of Military Actions in Chosun/Korea 1340-1700