Hosokawa Tadaoki was a veteran warrior and daimyo of the Warring States period. He fought his first battle under Oda Nobunaga at the age of 15, and participated in the Battle of Komaki-Nagakute (1584) and the Odawara Campaign (1590) fighting under Toyotomi
His father was the highly respected warrior, scholar, and poet Hosokawa Fujitaka, and like his father, Tadaoki was recognized as a man of the arts, particularly the tea ceremony, which he studied under the great Sen no Rikyu. Tadaoki was said to be a quick-tempered man and a ferocious fighter.
His wife was famous for her beauty and intelligence. The daughter of Akechi Mitsuhide, she entered the Christian religion, becoming known as Gracia.
When Mitsuhide attacked Nobunaga in the Honnoji incident, killing his former master, Mitsuhide turned to his son-in-law, Tadaoki for assistance. Tadaoki and his father, Hosokawa Fujitaka refused help, and Tadaoki was forced to send his wife into exile in the mountains around Kyoto for two years before confining her to the Hosokawa mansion in Osaka.
Prior to the Battle of Sekigahara, Ishida Mistunari, in an effort to quell the flow of Toyotomi loyalists defecting to the east, attempted to take the families of various daimyo hostage.
Things got out of hand on the subjugation of the Hosokawa house, and to escape the clutches of Ishida, Gracia had a servant spear her and set the mansion alight. The actions by Ishida and his men were considered an appalling act that merely drove more leaders away from the western causes.
At the Battle of Sekigahara, Tadaoki lead 5,000 samurai in some of the bloodiest fighting against the forces of Shima Sakon directly below Ishida Mitsunari on the slopes of Mt. Sasao. Following the great battle, Tadaoki was awarded a 370,000 koku fief in Kokura, Buzen, and following his actions in the 1614 and 1615 sieges of Osaka, and the Siege of Shimabara, received a 540,000 koku fief in Kumamaoto.
When he died at the age of 82 in 1646, he was interred next to his wife who had died some
45 years earlier. He had never remarried.
Tadaoki was the third to last of the remaining daimyo to have participated at Sekigahara, dying
4 years before Mori Hidemoto, and 9 years before Ukita Hideie.