Kuroda Nagamasa
In the Battle of Sekigahara on 1600, Hiroie judged that the Tokugawa side would win. However, as one of the five leading elders of the Toyotomi government, Mōri Terumoto and several of the Mōri clan's retainers was supportive of the pro-Toyotomi forces led by Ishida Mitsunari. In order to ensure the survival of the clan, Hiroie made a secret pact with the Tokugawa side through Kuroda Nagamasa, promising to Mōri neutrality during the battle in exchange for guarantees of the existing Mōri domains.