Although the Eastern Army was victorious, the soldiers of Mōri who did not participate in the battle and holed in the Osaka Castle were largely intact. Ieyasu feared that Terumoto would continue to resist by barricading himself in Osaka Castle with Hideyori. Therefore, on September 17, Ieyasu sent a letter to Terumoto to convince him to leave Osaka Castle by promise of a peaceful settlement between the two. As soon as the news of the Eastern Army's victory at Sekigahara reached Ogaki Castle, which at the time was still besieged by Mizuno Katsunari, Western Army-affiliated garrison commander
Akizuki Tanenaga immediately surrendered and opened the castle for Katsunari. In response, Katsunari immediately wrote to Ii Naomasa asking that Ieyasu pardon Tanenaga, which Ieyasu accepted. The most prominent political effect of the Eastern Army victory in Sekigahara was the shifting authority to assign
military ranks and redistribute lands from the Toyotomi clan to Tokugawa Ieyasu. Immediately following the battle, Ieyasu redistributed domains worth 6.8 million
koku, •
Ikeda Terumasa was reassigned from
Mikawa Province, Yoshida region to a 520,000-koku
domain in
Harima Province,
Himeji region. •
Tōdō Takatora was reassigned to a 200,000-koku domain in
Imabari, Ehime. •
Matsudaira Tadayoshi was reassigned from a 100,000-koku domain in
Musashi Province, Yuki region, to a 520,000-koku domain in
Echizen Province,
Fukui region. •
Yūki Hideyasu was reassigned from a 101,000-koku domain in
Shimōsa Province, Shinobu region, to a 569,000-koku domain in
Owari Province,
Kiyosu region. •
Gamō Hideyuki was reassigned from a 180,000-koku domain in
Shimotsuke Province,
Utsunomiya region, to a 600,000-koku domain in
Mutsu Province,
Aizu region. •
Maeda Toshinaga had his 835,000-koku domain in
Kaga Province,
Kanazawa region, expanded to 1,100,000 koku. •
Katō Kiyomasa had his 195,000-koku domain in
Higo Province,
Kumamoto region, expanded to 515,000 koku. • Kuroda Nagamasa was reassigned from a 180,000-koku domain in
Buzen Province,
Nakatsu region, to a 523,000-koku domain in
Chikuzen Province,
Fukuoka region. • Fukushima Masanori had his 200,000-koku domain in the area of contemporary
Aki District, Hiroshima, expanded to 498,000 koku. •
Horio Tadauji had his domains in Matsue, Izumo, expanded to 240,000 koku. •
Asano Yoshinaga was assigned to 376,560-koku domain and the control of Wakayama Castle in Kii Province. • Ieyasu also bestowed increases of at least into 10,000 koku to many of his
fudai daimyō (Tokugawa clan hereditary vassals) whose domain were less than 10,000 koku before the battle. Notably, Kobayakawa Hideaki, whose defection from the Western Army contributed greatly to Ieyasu's victory, was bestowed a domain which covered parts of
Bizen Province and
Mimasaka Province and which was worth 520,000 koku. This redistribution of domains was done verbally, instead of by formal
letter of intent. Historian Watanabe Daimon suspected this was because Ieyasu was still wary of the existence of Toyotomi clan which had been inherited by Toyotomi Hideyori. After that, Shigekado did not accompany the main force of the Eastern Army, which headed west. In the meantime, he captured Konishi Yukinaga, who had fled to Mount Ibuki, and delivered him to Ieyasu, who was advancing to Kusatsu in Omi. As appreciation, Ieyasu then bestowed upon him the sword that belonged to Yukinaga. Ieyasu bestowed smaller domain increases to the three remaining
Shitennō (Ii Naomasa, Honda Tadakatsu, and
Sakakibara Yasumasa), his closest high-ranking generals, as compared to those he offered to newer commanders and vassals. However, although Yasumasa indeed declined Ieyasu's offer for 250,000 koku of
Mito Domain, However, after his father, Iesada, died in 1608, through the intermediation of
Kōdai-in, he was granted his estate (25,000 koku in
Ashimori Domain, at
Bitchu Province) and was left to his discretion. Ieyasu had also decided to divide his estate between Katsutoshi and Toshifusa, but Kodaiin gave the entire estate to Katsutoshi as she favored him. Another Daimyo was
Miyabe Nagafusa, who was demoted and stripped from his title, due to slander by
Tanaka Yoshimasa that Nagafusa intended to defect to the Western Army, despite participating in the attack on Sawayama Castle as part of the Eastern Army. As for the generals of the defeated Western Army, roughly 87 daimyō had their domains confiscated and their power stripped due to their support of Mitsunari in the battle. The long-standing
Chōsokabe clan, headed by
Chōsokabe Morichika, was stripped of its title and domain of
Tosa Province, which was consequently given to
Yamauchi Kazutoyo in recognition of his service to the Tokugawa. Several former Chōsokabe retainers
resisted the forcible takeover by the Tokugawa and Kazutoyo; in response, Ii Naomasa sent military reinforcements to assist Kazutoyo in suppressing the rebellion of Chōsokabe vassals in Tosa. On September 17, Ieyasu dispatched his army, led by Kobayakawa Hideaki, to attack
Sawayama Castle in
Ōmi Province, the home base of Mitsunari. Most of the castle's troops had been sent to Sekigahara, leaving the castle's garrison with only 2,800 men. Despite Mitsunari's absence, the defense of the castle was initially successful under the leadership of Mitsunari's father
Ishida Masatsugu and brother Masazumi. Following the defection of retainer Moritomo Hasegawa and other defenders, the castle was opened to the besieging army; most of Mitsunari's relatives, including Masatsugu, Masazumi, and Mitsunari's wife Kagetsuin, were killed in battle or committed suicide. In response to
Shimazu Yoshihiro's support of the Western Army, Ieyasu prepared a massive punitive expedition to Kyushu, to be led by his son
Tokugawa Hidetada. This force was to be composed of Eastern Army forces thereupon engaged in the West, including the armies of
Katō Kiyomasa,
Kuroda Yoshitaka,
Nabeshima Naoshige, and the
Tachibana clan. However, this operation was aborted once
Shimazu Yoshihisa, the head of the
Shimazu clan, entered negotiations with Ieyasu. Shimazu-Tokugawa deliberations continued until 1602 and were aided by the intercession of Kiyomasa, Yoshitaka, and
Tachibana Muneshige; ultimately, the Shimazu clan avoided punishment, becoming the only Western Army-aligned clan to avoid losing territory after the defeat at Sekigahara. On November 6, Ishida Mitsunari,
Konishi Yukinaga and
Ankokuji Ekei were captured and executed. In 1603, Ieyasu was officially appointed as
shōgun by
Emperor Go-Yōzei. In 1931, the location of the battle was registered as a
Monument of Japan. The positions of Ieyasu and Mitsunari's armies, and that of the death of Ōtani Yoshitsugu, are commemorated therein. == Historical Analysis ==