The Warrior Era: Sumo & the Samurai
The History of Sumo Wrestling
Chapter 4 · The Warrior Era: Sumo & the Samurai
A New Ruling Class, a New Use for an Old Practice
As real political power shifted from the imperial court to a warrior aristocracy — the Kamakura shogunate's own founding is itself genuinely disputed among historians, with 1185 (when Minamoto no Yoritomo secured real judicial and policing authority over the eastern provinces) now generally favoured over the older, more traditional 1192 date (his formal imperial appointment as Seii Taishōgun) — sumo followed Japan's own shifting centre of power. The samurai who now genuinely ran the country had far less use for a court ceremony tied to harvest divination than for a real system of unarmed and semi-armed combat training.
Kumiuchi: Sumo as Battlefield Grappling
That training took shape as kumiuchi — literally "grappling combat" — real armored close-quarters wrestling, drawing directly on sumo technique. Warfare in this period followed a genuine, documented sequence: bow and arrow first, then swordwork, and finally, once combatants closed the distance completely, kumiuchi grappling. On a real medieval battlefield, an enemy general pinned to the ground in kumiuchi was typically finished off with a blade — the grappling itself was the step that decided who got to use the sword next.
Bow, then sword, then kumiuchi grappling once fighters closed — a real, documented progression through the stages of a medieval Japanese engagement.
Winning the grapple against an armored opponent decided who controlled the finishing blow — grappling skill had real, lethal stakes on the battlefield.
Sumo technique served as the practical foundation kumiuchi was built on, training the unarmed core skill underneath a form of combat carried out in full armor.
This is a genuine repurposing, not merely a rebranding. The ceremony Chapter 3 described was staged for the emperor's own court; kumiuchi was drilled for a battlefield where losing the grapple could mean losing your life. The techniques share real ancestry, but the stakes, and the audience, had changed completely.
Oda Nobunaga's Real, Documented Tournament
By the late sixteenth century, sumo had also become something the era's most powerful warlords used deliberately, in public, for their own political ends. Oda Nobunaga — the warlord whose own campaigns did more than any other single figure's to end Japan's long civil-war period — was a genuine, documented enthusiast of the sport, holding real sumo tournaments at Jōraku-ji in Azuchi repeatedly between 1570 and 1581, the year before his death.
Nobunaga's largest tournament was held in February 1578 at Azuchi Castle, with a documented 1,500 wrestlers taking part. Because so many bouts needed to run at once, circular arenas were marked out across the castle grounds specifically to speed the proceedings along and keep spectators safely clear of the action. The tournament drew genuine, verified strategic value beyond simple entertainment: it let Nobunaga scout young men of real physical strength and martial promise, while the scale of the spectacle itself was a real, deliberate display of his own authority.
It is tempting to read Nobunaga's 1578 circular arenas as the direct origin of sumo's own iconic circular ring — but the real record doesn't support that link cleanly. The formally codified, sacred circular dohyō — straw bales packed with earth, a fixed 13-shaku (roughly 3.94-metre) diameter — is documented instead from the Enho era, 1673 to 1681, nearly a century later, and is associated with kanjin-zumo, the fundraising matches covered in Chapter 5. Nobunaga's own circular arenas were a practical, event-specific solution to running many simultaneous bouts safely — a real precedent in shape, but not, on the current evidence, the direct ancestor of the single sacred ring later chapters describe.
Looking Ahead
Chapter 5 covers the Edo period, where sumo genuinely professionalises for the first time — kanjin-zumo fundraising matches, the real, formally codified circular dohyō this chapter deliberately deferred, and the banzuke ranking system that still structures the sport today.
Questions to Sit With
Kumiuchi kept sumo's own core technique but changed its purpose from ceremony to lethal battlefield skill. What does it take for a practice to be repurposed that completely while still being recognisably the same thing?
Nobunaga's tournament served both real entertainment and real strategic scouting at once. What does combining those two purposes in one event suggest about how a powerful ruler might use a popular sport for ends that have nothing to do with the sport itself?
This chapter deliberately resisted linking Nobunaga's circular arenas to the later, formally codified dohyō. Why might it matter to keep two similar-looking historical details separate, even when connecting them would make for a neater story?
Quick Reference — Chapter 4
- The Kamakura shogunate's real founding date is genuinely disputed — 1185 (Yoritomo's real judicial/policing authority) is now generally favoured over the traditional 1192 (his formal imperial appointment)
- Kumiuchi — real armored grappling combat — drew directly on sumo technique as part of the documented bow-then-sword-then-grapple sequence of medieval battlefield combat
- Oda Nobunaga held real sumo tournaments at Jōraku-ji in Azuchi from 1570 to 1581, his largest in February 1578 with 1,500 wrestlers
- Temporary circular arenas at that tournament sped up simultaneous bouts and protected spectators — a real, practical, event-specific solution
- An honest distinction: the formally codified, sacred circular dohyō is documented separately, from the Enho era (1673–1681), and is not directly traceable to Nobunaga's own 1578 arenas