In the 11th century, Shigetsugu of the Chichibu clan built his own residence (later, the Edo Castle) on a hill overlooking Sakurada, and founded the EDO clan by renaming himself EDO Taro after the place name Edo.
11世紀に秩父氏から出た江戸重継は、江戸の桜田（のちの江戸城）の高台に居館を構え、江戸の地名をとって江戸太郎を称し、江戸氏を興す。