During the late Heian period, Sohei became powerful armed groups with their stronghold including at Kofuku-ji Temple, Enryaku-ji Temple, Onjo-ji Temple and Todai-ji Temple and were repeatedly involved in power struggles among temples or in acts of menace to the imperial court and Sekke (line of regents and advisers).
平安時代末期には強大な武力集団となり、興福寺・延暦寺・園城寺、東大寺などの寺院を拠点として、寺院同士の勢力争いや、朝廷や摂家に対して強訴をくりかえした。