Why did the Western Army lose despite having superior numbers?
The Western Army’s structural weakness—a coalition of shogunal administrators and independent warlords without unified command—was compounded by pre-battle defections. Multiple commanders had secretly agreed to support the East. Kobayakawa’s defection was the visible symbol; Kikkawa’s engineering of Mori inaction was equally fatal.
Why was Ishida Mitsunari unpopular among the warlords?
Mitsunari served as Toyotomi Hideyoshi’s commissioner, responsible for administration and logistics. His strict oversight generated friction with the “military merit” faction (generals like Katō Kiyomasa and Fukushima Masanori). This civil-military divide emerged in Hideyoshi’s final years, and many military commanders sided with Ieyasu at Sekigahara partly to be rid of Mitsunari.
Why was the battle decided in a single day?
Both armies faced each other in morning fog. Once the fog lifted, fighting began, and Kobayakawa’s defection reportedly occurred in the early afternoon. The Western Army collapsed rapidly because its organizational coherence had already been undermined by prior defections—not because of any single tactical genius.