Kenji (建治) is a Japanese era name (年号, nengō, lit. "year name") which followed Bun'ei and preceded Kōan. This period spanned the years from April 1275 to February 1278.[1] The reigning emperor was Go-Uda-tennō (後宇多天皇).[2]
1275 Kenji gannen (建治元年): The new era name was created to mark an event or a number of events. The previous era ended and a new one commenced in Bun'ei 12. The era name comes from the Rites of Zhou and combines the characters 建 ("build, establish") and 治 ("govern").
1275 (Kenji 1): The Mongols sent an ambassador to Kamakura along with the delegation which accompanied the envoy from the Goryeo. The unwelcome visitor was put to death; and his severed head was publicly displayed.[3]
November 23, 1275 (Kenji 1, 5th day of the 11th month): Hirohito-shinnō was named Crown Prince and heir to his first cousin, the Daikakuji-tō Emperor Go-Uda. This was the result of political maneuvering by Hirohito's father, the Jimyōin-tō Emperor Go-Fukakusa.[4]
1277 (Kenji 3, 5th month): Yoshimasa laid down his office.[5]