in 1524, ujitsuna took edo castle, which was controlled by uesugi tomooki, thus beginning a long-running rivalry between the hōjō and uesugi families. two years later, the uesugi attacked and burned kamakura, which was a major loss to the hōjō symbolically, because the earlier hōjō clan from which they took their name fell in the siege of kamakura in 1333.