Uesugi Clan - Sengoku Period

Sengoku Period

Traditionally the Ōgigayatsu relied on the Ōta clan, while the Yamanouchi relied on the Nagao of Echigo Province as the pillars of their strength. Ōta Dōkan, a vassal of the Ōgigayatsu Uesugi, who were less numerous than their Yamanouchi cousins, lent them a great boost of power by building Edo castle for them in the 1450s. On the other hand, Nagao Tamekage, Deputy Constable of Kamakura in the first decades of the 16th century, allied himself with Hōjō Sōun, who would later become one of the Uesugi's strongest rivals.

The expansion of the Hōjō into the lower Kantō forced the two branches of the Uesugi to become allies. In 1537, Kawagoe fell to Hōjō Ujitsuna. Then in 1545, both of the branches of the Uesugi shared defeat, and attempted to regain their power. However, the Ōgigayatsu branch family came to an end with the death of Uesugi Tomosada, during a failed attempt to retake Kawagoe castle that year. Uesugi Norimasa, the holder of Hirai castle, which had fallen in 1551 to the Hōjō, took up arms with his retainer, Nagao Kagetora in Echigo. Kagetora then adopted the surname of "Uesugi" after campaigning against the Hōjō in Sagami Province; he would later take the name Uesugi Kenshin, and become one of Sengoku's most famous generals, battling the Hōjō and Takeda Shingen for control of the Kantō.

At the end of the Sengoku period, Kenshin's adopted son Uesugi Kagekatsu, then head of the clan, was a supporter of Ishida Mitsunari during the battle of Sekigahara. As a result of being on the losing side of the conflict, the Uesugi were afterwards much reduced in power.