Yoshiaki was one of Hideyoshi's seven most trusted and experienced generals. He was involved in the bitter naval battles at Siege of Shimoda in the Odawara Campaign (1590) and fought off the coast of southern Korean peninsula during the 1st and 2nd Korean Campaign, many of which went in favor of the Korean navy.
Conflict with Ishida Mitsunari
According to popular theory In 1598 after the death of Toyotomi Hideyoshi, the government of Japan have an accident when seven military generals consisted of Fukushima Masanori, Katō Kiyomasa, Ikeda Terumasa, Hosokawa Tadaoki, Asano Yoshinaga, Katō Yoshiaki, and Kuroda Nagamasa planned a conspiracy to kill Ishida Mitsunari. It was said that the reason of this conspiracy was dissatisfaction of those generals towards Mitsunari as he wrote bad assessments and underreported the achievements of those generals during the Imjin war against Korea & Chinese empire.[2] At first, these generals gathered at Kiyomasa's mansion in Osaka Castle, and from there they moved into Mitsunari's mansion. However, Mitsunari learned of this through a report from a servant of Toyotomi Hideyori named Jiemon Kuwajima, and fled to Satake Yoshinobu's mansion together with Shima Sakon and others to hide.[2] When the seven generals found out that Mitsunari was not in the mansion, they searched the mansions of various feudal lords in Osaka Castle, and Kato's army also approached the Satake residence. Therefore, Mitsunari and his party escaped from the Satake residence and barricaded themselves at Fushimi Castle.[3] The next day, the seven generals surrounded Fushimi Castle with their soldiers as they knew Mitsunari was hiding there. Tokugawa Ieyasu, who was in charge of political affairs in Fushimi Castle trying to arbitrate the situation. The seven generals requested Ieyasu to hand over Mitsunari, which refused by Ieyasu. Ieyasu then negotiated the promised to let Mitsunari retire and to review the assessment of the Battle of Ulsan Castle in Korea which became the major source of this incident, and had his second son, Yūki Hideyasu, to escort Mitsunari to Sawayama Castle.[4] However, historian Watanabe Daimon stated from the primary and secondary sources text about the accident this was more of legal conflict between those generals with Mitsunari, rather than conspiracy to murder him. The role of Ieyasu here was not to physically protect Mitsunari from any physical harm from them, but to mediate the complaints of those generals.[5]
Nevertheless, historians viewed this incident not just as simply personal problems between those seven generals and Mitsunari, but rather as an extension of the political rivalries of greater scope between the Tokugawa faction and the anti-Tokugawa faction led by Mitsunari. Since this incident, those military figures who were on bad terms with Mitsunari would later support Ieyasu during the conflict of Sekigahara between the Eastern army led by Tokugawa Ieyasu and the Western army led by Ishida Mitsunari.[2][6] Muramatsu Shunkichi, writer of "The Surprising Colors and Desires of the Heroes of Japanese History and violent womens”, gave his assessment that the reason of Mitsunari failure in his war against Ieyasu was due to his unpopularity among the major political figures of that time.[7]
In 1600, Katō fought alongside Tokugawa Ieyasu. Following the important victory at Sekigahara in 1600, Tokugawa doubled Katō's fief from 100,000 koku to 200,000. For a time, he was lord of Aizu.
^Turnbull, Stephen (1998). The Samurai Sourcebook. London: Cassell & Co. p. 34,49,234,241. ISBN9781854095237.
^ abcMizuno Goki (2013). "前田利家の死と石田三成襲撃事件" [Death of Toshiie Maeda and attack on Mitsunari Ishida]. 政治経済史学 (in Japanese) (557号): 1–27.
^Kasaya Kazuhiko (2000). "豊臣七将の石田三成襲撃事件―歴史認識形成のメカニズムとその陥穽―" [Seven Toyotomi Generals' Attack on Ishida Mitsunari - Mechanism of formation of historical perception and its downfall]. 日本研究 (in Japanese) (22集).
^Kasaya Kazuhiko (2000). "徳川家康の人情と決断―三成"隠匿"の顚末とその意義―" [Tokugawa Ieyasu's humanity and decisions - The story of Mitsunari's "concealment" and its significance]. 大日光 (70号).
