Medieval Temples and Arms — Sohei Swords and Their Influence on Japanese Sword Development

Medieval Japanese military power was not the sole preserve of warriors and courts. From late Heian through Sengoku, major temples such as Enryaku-ji on Mt. Hiei, Kofuku-ji, Todai-ji, and Onjo-ji (Mii-dera) maintained thousands of sohei (monk-warriors), sometimes challenging even the warrior government. Their weapons — particularly naginata and swords — form a significant chapter in medieval Japanese arms history.

This article explores sohei as unique armed collectives and their influence on Japanese sword development.

Who Were the Sohei?

Sohei were armed monks and armed lay servants affiliated with temples. Technically religious (shaven-headed and robed), they transformed into full warriors in battle, wearing face veils, armor, and weapons. They acted aggressively to defend temple lands, pursue factional interests, and apply political pressure, sometimes descending on Kyoto to pressure the imperial court through "forceful protest."

From the 11th century, temples became economic powers holding vast shoen (estates). Protecting these required independent armed force. In an era when reliance on court or shogunate alone was insufficient, temples armed themselves for self-defense.

Naginata — The Symbolic Sohei Weapon

The weapon most associated with sohei is the naginata — a curved blade mounted on a long shaft, combining wide-sweeping mobility with advantage against mounted warriors.

Several reasons explain naginata's development as a sohei weapon:

First, long-hafted weapons were needed to counter mounted warriors. Sohei were mostly infantry, making long-reach naginata highly effective against cavalry. Second, in large-scale melees, naginata could strike multiple enemies efficiently. Third, naginata training was part of monastic discipline combining martial and spiritual practice.

Musashibo Benkei, portrayed as a naginata master, reflects this sohei culture.

Swords Were Also Essential

Despite strong naginata imagery, swords were equally important sohei armament. Close and hand-to-hand combat often favored swords over long weapons, and sohei habitually carried tachi or koshigatana.

Notably, most sohei swords were "practicality-focused" compared to the ornate styles of the time. Durability and handling outweighed decoration and complex hamon, shaping one wing of medieval Japanese practical-blade development. The Yamato tradition (Nara) with its tall shinogi and robust construction relates deeply to Kofuku-ji and Todai-ji sohei demand.