At this time, the main force of Ieyasu and the advance party of daimyo who were assisted by Toyotomi proceeded on Tokai-do Road, but 38,000 troops led by Hidetada TOKUGAWA went west on the Nakasen-do Road.

At that time, Hideyoshi TOYOTOMI, a vassal of Nobunaga's, who was in Bicchu (the western part of Okayama Prefecture) as a commander in chief of the forces coming from around the Chugoku region, immediately made a peace treaty with Terumoto MORI, lead his army back east and killed Mitsuhide AKECHI (the Battle of Yamazaki).

Ieyasu Tokugawa's establishing the Edo Bakufu (Edo shogunate) as Seiitaishogun (commander-in-chief of the expeditionary force against the barbarians, great, unifying leader) in 1603 put an end to the Toyotomi government.

It is said that after Hideyoshi's failure to accomplish his desire to become 'Seii Taishogun', he introduced a new system, 'the Kanpaku system by the samurai family' instead of the 'Bakufu' system; the status of 'Kanpaku' was given to him through accidental events, and he tried to change the status to the Toyotomi-clan hereditary system (by excluding five Fujiwara Gosekke (five top Fujiwara families whose members were eligible for the positions of Sessho and Kanpaku)).

Meanwhile, Hideyoshi TOYOTOMI, who had brought his old enemy Ieyasu TOKUGAWA into subjection to ensure future security, decreed a large-scale mobilization order in February, 1587 for the Kyushu Conquest, and sent a large army of daimyo (Japanese feudal lords) from Kinai (the five capital provinces surrounding the ancient capitals of Nara and Kyoto), Chugoku and Shikoku regions to Kyushu.

In April, the forces of Hidenaga TOYOTOMI, who was Hideyoshi's younger brother, joined the Chugoku forces of Terumoto MORI, Hideie UKITA, and Keijun MIYABE who had already arrived at Buzen Kokura, making a 100,000-strong Toyotomi army.

However, soon after the Funai-jo Castle was attacked by the Toyotomi's army, Yoshihiro SHIMAZU realized that the enemy's forces and supplies far exceeded his own, so he escaped Funai-jo Castle by sea in the midst of a midnight storm on April 22 and retreated to Matsuo-jo Castle where his younger brother Iehisa was on guard.

According to Nisshu Shonai Gunki, there is an entry stating that Mitsunari ISHIDA or Ieyasu TOKUGAWA told Tadatsune, who had returned from Korea after the death of Hideyoshi TOYOTOMI, that Tadamune IJUIN was thinking of rebellion, but there is no other historical evidence of the same era to prove it.

However, they are said to have taken a no cooperative stance toward Nobunaga ODA because they were attendants to the Shogun, so at the Honnoji Incident in 1582 Yoritsugu NOSE supported Mitsuhide AKECHI and after Mitsuhide was destroyed by Hideyoshi TOYOTOMI Yoritsugu was forced from Nose and hid in Bizen Province, which was associated with his ancestor Yorisada TADA.

Tozama daimyo, who began to serve the Tokugawa clan after the Battle of Sekigahara (including the Toyotomi-related daimyo who fought as the East squad in the Battle of Sekigahara).

After the death of Hideyoshi TOYOTOMI, Ieyasu TOKUGAWA, one of the Gotairo (Council of Five Elders), strengthened his power in the Toyotomi administration, and at the Battle of Sekigahara in which a former member of the Gobugyo (five major magistrates) Mitsunari ISHIDA and others uprose in 1600, he commanded the Eastern Army and rebuffed Mitsunari's Western Army.

It meant that the Toyotomi Family no longer ruled Japan, but the Tokugawa Family did, however, Hideyori also steadily kept rising in official court rank to be Udaijin (minister of the right), while Hidetada was Naidaijin (minister of the center) when he became Shogun.

It is said that the bakufu was afraid that people who have been favored by the Toyotomi family would betray the bakufu, however, it would not apply to Nagamasa KURODA, who contributed to the victory of the Eastern Army at the Battle of Sekigahara.

Charges by Nobushige SANADA, Katsunaga MORI, Harufusa ONO and so on on the Toyotomi side killed and injured daimyo, officers and soldiers on the bakufu side and put the headquarters of Ieyasu/Hidetada in a great confusion, however, the bakufu army surpassing in forces, gradually recovering from chaos, regained its balance, while the Toyotomi army, having lost many officers and soldiers, was destroyed at about 3:00 pm.

Toyotomi Army (Toyotomi Family)

Although Asakura and Azai troops were understrength, Azai's elite troops led by its top Kazumasa ISONO broke through those of Oda's top Masahisa SAKAI, Tsuneoki IKEDA, Hideyoshi TOYOTOMI and Katsuie SHIBATA one after another, and in fact, they launched fierce attacks to knock down eleven out of thirteen layers of military reserves.

Ieyasu TOKUGAWA, a member of the Gotairo (Council of Five Elders) of the Toyotomi government, was appointed Seii Taishogun (literally, "great general who subdues the barbarians") after the Battle of Sekigahara in 1600 and began to establish the Edo bakufu in Edo.

Although Yuhitsu existed in the Tokugawa clan as a warring lord, because those Yuhitsu who were working for Ieyasu TOKUGAWA when he was in Mikawa Province were appointed to administrative posts, such as Bugyo or Daikan, or Fudai Daimyo (a daimyo in hereditary vassal to the Tokugawa family) as Ieyasu expanded his influence and subdued various regions to unify Japan, it is thought that many of them who were hired as Yuhitsu when the Edo Bakuhu was established were the children of the Bugyo-shu belonged to the former Muromachi Bakuhu (Naosuke SOGA), the Yuhitsu-shu of the Toyotomi government (Shigeyasu OHASHI), supported the 'eastern' army at the Battle of Sekigahara, and the Yuhitsu of the former Gohojo clan, served Ieyasu when he subdued Kanto region.

He is also believed to have played a role in the preservation of the Toyotomi clan after the clan's defeat in the Battle of Sekigahara, by keeping distance from Mitsunari ISHIDA and others in the West (Toyotomi) camp and negotiating secretly with Ieyasu TOKUGAWA.

Nagamasu ODA, who is a younger brother of Nobunaga ODA and was famous as a master of tea ceremony, contributed to the East camp at the Battle of Sekigahara and gave distinguished war service; however, after the war he became the vassal of Toyotomi clan for the reason that he is a granduncle of Hedeyori TOYOTOMI.