holding of Kiyosu and to seize Gifu Castle from Oda Hidenobu. The combined 31,000 troops of this "Tōkaidō Corps" quickly besieged Gifu on 28 September and forced the capitulation of Hidenobu. Meanwhile in Ōsaka, Mōri clan retainer Kikkawa Hiroie was enraged by Mitsunari confining Mōri Terumoto, nominal commander-in-chief of the Western Army, to the castle, and in response to the insult Hiroie secretly communicated with the Tōkaidō Corps promising to keep the 36,000 Mōri troops from engaging the Eastern Army. Mōri Hidemoto, Terumoto's cousin and deputy, also urged Terumoto to defect to the Eastern Army before any engagement occurred. On 29 September, the Tōkaidō Corps occupied the highlands of Akasaka to threaten Ōgaki Castle as Nabeshima Naoshige besieged the Eastern Army stronghold of Matsuoka Castle. The following day, 30,000 Western troops under Mori Hidemoto, Chōsokabe Morichika, and Nabeshima Katsushige besieged An'nōzu Castle, held by Fukuda Nobutaka and his 1,700-strong garrison. Ishida Mitsunari left Ōgaki Castle on 1 October for Sawayama Castle, where he relented and summoned Mōri Terumoto, who had returned to his own domain to raise troops, to return; one messenger was intercepted, and though a second messenger succeeded in prompting Terumoto to depart with his 30,000 troops, they were delayed from reaching the major confrontations. Ieyasu moved quickly towards the capital region, reaching Shimada in Suruga Province on 12 October and Nakaizumi in Totomi Province the following day. At the same time, Mōri Hidemoto and Kikkawa Hiroie entered Mino Province and fortified Mount Nangu. During this march, Ieyasu received a letter from Western Army commander Kobayakawa Hideaki offering to defect to the Eastern Army. On 17 October Ieyasu reached Kiyosu Castle, intending to bypass Ōgaki entirely to threaten Sawayama Castle or Ōsaka, and 2 days later he had arrived at Gifu Castle. Ieyasu arrived in Akasaka around noon on 20 October, meeting up with the main body of the Tōkaidō Corps, and encamped on the hill at Okayama. Western Army generals convinced Mitsunari to permit a testing raid, and Shima Sakon and Akashi Masataka led a small force to attack the Eastern Army at the Kuisegawa river near Ōgaki, mauling the Eastern Army and forcing them to retreat to Sekigahara to regroup. That night, Shimazu Yoshihiro with Ukita Hideie's support suggested a night assault on the exhausted Eastern Army troops, but was opposed by Shima Sakon who convinced Mitsunari to decline the proposal, insulting Yoshihiro. Mitsunari instead ordered