Siege of Musashi-Matsuyama

What Happened

In the first month of 1537, forces of the Hōjō clan took Matsuyama Castle in Musashi province from the Uesugi clan. The castle stood on a hilltop in the north of the province, at the coordinates 36.0375° N, 139.4206° E — the site of the modern city of Tsurugashima, in Saitama Prefecture. The engagement is dated to 1 January 1537, the sixth year of the Tenbun era.

The castle's Uesugi garrison, facing a Hōjō assault, attempted to summon help from outside. The appeal was concealed inside a dog's collar and carried out of the besieged castle. The message did not bring relief in time, and the castle fell to the Hōjō.

The siege was the first of several contests for Matsuyama Castle during the Sengoku period. The Uesugi later recovered the castle, and lost it again in 1563.

Background

By 1537 Japan had been in the Sengoku period (戦国時代, sengoku jidai, "Warring States period") for roughly seventy years, and the authority of the Muromachi shogunate in Kyoto had largely collapsed. Power lay with regional daimyō (大名, "great names") who fought one another for land, castles and the loyalty of local warriors. The Kantō region, the plain around modern Tokyo, was contested between two such houses: the Uesugi, who held the traditional shogunal deputy's office for the east, and the Hōjō, a newer power based at Odawara.

Musashi province (武蔵国, Musashi no kuni) covered the area of modern Tokyo and Saitama. Matsuyama Castle sat on its northern edge, guarding routes across the Kantō plain, and control of it mattered to both houses. In 1537 the castle was in Uesugi hands. The Hōjō moved against it in the sixth year of the Tenbun era (天文, Tenbun), an era name that had been in use since 1532.

Why It Mattered

The fall of Matsuyama Castle in 1537 pushed the Hōjō's frontier north and weakened Uesugi control of northern Musashi. It was the opening move in a long struggle for the castle: the Uesugi regained it at some point after 1537, and the Hōjō took it from them again in 1563. The castle thus changed hands repeatedly across the Sengoku period, a pattern typical of the era's hilltop fortresses on contested borders.

The siege is also remembered for the dog-collar message. Concealing a plea for reinforcements in an animal's collar was an ingenious attempt to break through a besieging army's lines, and its failure illustrates how tightly a besieging force could seal off a castle. The episode survives as a vivid anecdote of Sengoku communication and siegecraft.

The Name in Japanese

The Japanese name of the engagement is 松山城風流合戦, read まつやまじょうふうりゅうがっせん (Matsuyama-jō fūryū gassen). The romaji is Matsuyama-jō fūryū gassen.

Breaking it down character by character:

• 松 (まつ, matsu) — "pine tree."
• 山 (やま, yama) — "mountain." Together 松山 (Matsuyama) means "pine mountain," the name of the castle and the hill it stood on.
• 城 (じょう, jō) — "castle." In this compound it is read じょう; on its own the character can also be read しろ (shiro). 松山城 is "Matsuyama Castle."
• 風 (ふう, fū) — "wind," and by extension "style" or "manner."
• 流 (りゅう, ryū) — "flow" or "current." Together 風流 (ふうりゅう, fūryū) originally meant "elegant," "refined" or "in good taste" — a word with literary associations. In the name of a battle it carries an ironic flavour, a stylish or celebrated contest.
• 合 (がっ, ga') — "to join" or "to match." The reading がっ is a sound change (rendaku) of かつ.
• 戦 (せん, sen) — "battle" or "war." Together 合戦 (かっせん, kassen; here がっせん, gassen) means "battle" or "engagement."

So the full name reads literally as "the elegant battle of Matsuyama Castle." The word 合戦 is the standard term for a pitched battle in premodern Japanese chronicles, and appears in the names of many Sengoku engagements. Note that the castle's name, 松山, is shared by several other castles in Japan; the Musashi (武蔵) in the English title distinguishes this one, in Musashi province, from the better-known Matsuyama Castle in Iyo province on Shikoku.

Key Figures

The sources for this engagement name no individual commanders on either side. The principal actors are the two clans:

• The Uesugi clan (上杉氏, Uesugi-shi) — holders of Matsuyama Castle in 1537, and the defenders. The Uesugi were a major Kantō house; the branch involved in the northern Musashi fighting was the Ōgigayatsu line, though the sources for this siege do not name its commander.
• The Hōjō clan (北条氏, Hōjō-shi) — the attackers, based at Odawara in Sagami province. The Hōjō were the rising power in the Kantō in the 1530s, and the capture of Matsuyama Castle was one of their advances into Musashi.

The garrison's anonymous messenger, who carried the appeal for help hidden in a dog's collar, is the one human detail the record preserves of the men inside the castle.