Uesugi Masatora

...In addition, when Kanto Kanrei Uesugi Norimasa fled to Echigo in 1552 due to the pressure of the Later Hojo clan, Uesugi had to send troops to the Kanto region as well. In 1561, he led the Kanto Echigo army to besiege Hojo Ujiyasu at Odawara, but as the situation remained unchanged, he left the siege and returned to Kamakura, where he took the Uesugi surname and the Kanto Kanrei position that Norimasa had given him at Tsurugaoka Hachimangu Shrine, and changed his name to Uesugi Masatora. After returning to Japan, he fought in the aforementioned Fourth Battle of Kawanakajima, and at the end of the year he returned to Kanto again to fight against Hojo Ujiyasu, spending the New Year there. From this time on, he took the name Terutora, using the first part of the name of the Muromachi Shogun Ashikaga Yoshiteru.

*Some of the terminology that refers to "Uesugi Masatora" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…また，後北条氏の圧迫によって52年関東管領上杉憲政が越後に逃れて来ると，その後は関東方面にも兵を送らねばならなくなった。61年，関東越後の軍兵をひきいて長駆小田原に北条氏康を攻囲したが，事態の変化のないまま囲みをといて鎌倉にひき返し，鶴岡八幡宮で憲政から譲られた上杉姓と関東管領職をつぎ，名を上杉政虎と改めた。帰国後に前述の第4次川中島合戦を戦い，年末には再び関東に出て北条氏康と戦って越年したが，このころから室町将軍足利義輝の偏諱（へんき）をうけて輝虎と称する。…

※「上杉政虎」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報