In the 16th century, former peasant Toyotomi Hideyoshi united the warring factions of Japan, and invaded Korea and China, which kept the warrior nobility, the samurai, occupied. But upon his death, his heir, Hideyori, was too young to rule. To appease the noble families, five separate regents were appointed to rule in his stead.

By 1600, these disparate regents and the families had divided themselves into two factions vying for the shogunate, a position Hideyori could not hold due to his father’s low birth. The first faction, which had a power base in Western Japan was led by Ishida Mitsunari, a renowned politician but one with little military skill. He based his claim for the shogunate on his support for Hideyori. The second was led by Tokogawa Ieyasu, a general of great renown who was a warlord in the service of Hideyoshi’s chief rival, so had no great love for his son Hideyori.

In the heavy mist on the morning of 21 October, 1600, Ishida’s Army of the West met Tokgawa’s Army of the East at the pass at Sekigahara for control of the shogunate. Tokogawa immediately attacked hoping to catch his opponent unaware but the confusion of the fog and the smoke from the matchlock muskets devolved the battle into one of attrition. This suited Ishida because he outnumbered Tokagawa, and eventually the battle swung into his favor. As the sun burned away the mist he signaled Kobayakawa Hideyoki, whose forces were still uncommitted, to fall upon Tokogawa for a coup de grace.

But he didn’t. Kobayakawa’s forces charged not into the Army of the East, but into the flank of a completely surprised Army of the West. Tokogawa was more the politician than Ishida gave him credit for, and Kobayakawa betrayed Ishida. Ishida’s army attempted to fight on, particularly the Otani clan, whose valour was praised by all participants, but soon three more clans turned sides. Ishida’s army broke, and Ishida himself was captured and executed.

Tokogawa Ieyasu became shogun and the Tokogawa Shogunate ruled Japan for nearly three centuries until the Meiji Restoration in 1868.