Kato no ran

• Date: 1537-early 1550s

In 1537, Imagawa Yoshimoto made peace with Takeda Nobutora of Kai, marrying his daughter, (shingen's older sister Joukei-In). At this time, the Takeda had been considering invading Shinano province, and now with Yoshimoto married to the daughter of Nobutora, the Takeda could go forward with the Shinano invasion and not have to worry about being attacked from behind by the Imagawa. Obviously the Takeda saw great merit in this political marriage, as they could put all of thier efforts into invasion.

Furthermore, for the Imagawa, who had been subservient in power to the Hojo until now, they could gain some advantage and independence. Unfortunately, this angered Hôjô Ujitsuna, who had supported Yoshimoto during the Imagawa conflict during the Hanagura no Ran. At this time, the Hojo and Takeda were in conflict, and Ujitsuna had felt as though he were Yoshimoto's benefactor in helping him during the Hanagura no Ran and took this marriage as an affront. The Hôjô attacked the Imagawa, however were repelled. The Hojo attacked again in 1554, however, the reality was that neither side really wanted to fight, because they both had thier own agendas, and eventually made peace with the Hojo-Takeda-Imagawa Alliance in the mid-1550s.

References

• Kanaya, Shunichiro. Sengoku Jidai ga Omoshiroku Wakaru Hon (戦国時代が面白くわかる本) Japan, 2003
• Joukei-In From Japanese Wikipedia