伊豆國
Tadaoki was present on Hideyoshi's side in the Battle of Komaki and Nagakute (1584) and the Odawara Campaign (1590), where he took part in the siege of Nirayama (Izu Province) and later joined the main army outside Odawara. During the 1590s he became friends with Tokugawa Ieyasu (who had lent him money to assist in some debts owed Toyotomi Hidetsugu) and in 1600 sided with him against Ishida Mitsunari.