Japan in World War II

The military history of Japan is characterized by a period of clan warfare that lasted until the 12th century AD. This was followed by feudal wars that culminated in military governments known as the "Shogunate". Feudal militarism transitioned to imperial militarism in the 19th century after the landings of Admiral Perry and the elevation of the Meiji Emperor. This led to rampant imperialism until Japan's defeat by the Allies in World War II. The Occupation of Japan marks the inception of modern Japanese military history, with the drafting of a new Constitution prohibiting the ability to wage war against other nations.

Recent archaeological research has uncovered traces of wars as far back as the Jōmon period (ca. 10,000–300 BC) between the various tribes existing on the Japanese Archipelago. Some theorists believe that shortly after the Yayoi period (ca. 300 BC – 250 AD) horse riders from the Korean Peninsula invaded southern Kyūshū, then spread to northern Honshū. At this time, horse-riding and iron tools were first introduced to the islands.

Near the end of the Jōmon period (ca. 300 BC), villages and towns became surrounded by moats and wooden fences due to increasing violence within or between communities. Battles were fought with weapons like the sword, sling, spear, and bow and arrow. Some human remains have been found with arrow wounds.

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