The Oshu Fujiwara clan prospered over a hundred years for four generations, FUJIWARA no Kiyohira, FUJIWARA no Motohira, FUJIWARA no Hidehira, and FUJIWARA no Yasuhira; and Hiraizumi became the second biggest city in Japan next to Heiankyo (ancient Kyoto).
奥州藤原氏は藤原清衡、藤原基衡、藤原秀衡、藤原泰衡と4代100年に渡って繁栄を極め、平泉は平安京に次ぐ日本第二の都市となった。