The man who would become shogun of all Japan rode away in the early morning light, and reportedly wept the entire night before he did it.

Tokugawa Ieyasu was fifty-seven years old on July 26, 1600 — a veteran of a lifetime of wars, betrayals, and calculated sacrifices. He understood power the way a surgeon understands anatomy: precisely, without sentiment. And yet later chronicles record that he could not stop weeping as he prepared to leave Fushimi Castle and the friend he was leaving there to die.

The political logic was iron-clear. Ieyasu needed to march east and consolidate his forces before Ishida Mitsunari's western coalition sealed off the roads. Fushimi Castle sat astride the route those forces would take. Someone had to hold it — not to win, which was impossible against forty thousand attackers, but to delay long enough for Ieyasu to gather his 東軍 (Tōgun), his Eastern Army. His 四天王 (Shitennō) general Torii Mototada had asked to stay. He had insisted. Ieyasu could not refuse the gift, even knowing its cost.

He rode east. Behind him, Mototada organized his garrison of roughly 1,800. The western coalition's siege began August 27. The defenders held for twelve days, a ratio of more than twenty attackers for every man inside the walls. When the keep was finally breached and set ablaze, Mototada died by seppuku with his last ten surviving men, refusing capture to the end.

Ieyasu never saw him again. Forty-three days after Fushimi fell, on October 21, 1600, Ieyasu's army met the western coalition at Sekigahara and destroyed it before nightfall. Three years later, Ieyasu became 征夷大将軍 (Seii Taishōgun), supreme military ruler of Japan. The Tokugawa dynasty would govern — in unbroken succession — for 265 years.

Whether Ieyasu's tears were real or the invention of later storytellers, the story persisted because it captured something true about the price of power: that the men who build dynasties do so by spending other men's lives. And sometimes those other men are their oldest friends.