Futamata Castle

Overview

Futamata Castle (二俣城, Futamata-jō) is a ruined Japanese castle in Tenryū-ku, a ward of the city of Hamamatsu in Shizuoka Prefecture. It sits at coordinates 34.8620250, 137.8089333, on ground that once belonged to Toyoda county in Tōtōmi Province. The castle was founded in 1503, the third year of the Bunki era (文亀, Bunki), during the Muromachi period. It is remembered above all as the place where Matsudaira Nobuyasu, the eldest son of Tokugawa Ieyasu, died in 1579, and as the object of a siege that bears its name. In 2018 the ruins were designated a National Historic Site together with the adjacent Tobayama Castle (鳥羽山城, Tobayama-jō).

History

Futamata Castle was built in 1503, in the third year of the Bunki era, placing its foundation in the Muromachi period. The site controlled the Tenryū river valley, and its position made it a natural point of contention as the surrounding province changed hands.

The castle's most famous episode is the Siege of Futamata. The siege is the event for which the site is referenced in historical records, and it is the conflict tied to the castle's name. The castle's fall opened the way for its later role as a Tokugawa holding.

That later role is bound up with the death of Matsudaira Nobuyasu, Tokugawa Ieyasu's eldest son, in 1579. Nobuyasu's death is recorded with Futamata Castle as the place of death. The castle thus carries two distinct associations: a military struggle over the fortress itself, and the death of a Tokugawa heir within its walls.

What Stands There Today

The castle survives as ruins. No original keep or main tower stands; what remains is the footprint of the fortifications on the hillside above the Tenryū area of Hamamatsu. The site is a castle ruin of the kind common across Japan, where earthworks, ditches and layout survive rather than buildings.

In 2018 the ruins were recognised as a National Historic Site. The designation was made jointly with Tobayama Castle, the neighbouring fortification, so the two are protected and interpreted as a single historic landscape. Visitors encounter the two sites together rather than Futamata in isolation.

The Name in Japanese

The castle's name in Japanese is 二俣城. Its reading in kana is ふたまたじょう, and in romaji it is Futamata-jō.

Broken down character by character:

• 二 — read here as futa. This is the numeral two. It is the same character used in 二つ (futatsu), the native Japanese counting word for "two," and it appears in countless place names and compounds.
• 俣 — read here as mata. This character means a fork, a crotch, or a branching point, and it is used in place names to describe land where a river or road splits. It is a relatively rare kanji outside geography, which is why it appears most often in names like this one.
• 城 — read here as jō. This character means castle or fortress. When it follows a place name, it names the castle of that place, so 二俣城 is literally "the castle of Futamata."

The first two characters together, 二俣, mean "two forks" or "the place where the water divides." The name describes the geography: the site sits where the Tenryū river system branches. The reading Futamata is the native Japanese reading of those two characters, while jō is the Sino-Japanese reading of 城. This mix of native and Sino-Japanese readings in a single name is entirely ordinary in Japanese place and castle names.

For learners, the useful takeaway is the pattern: a geographic description in native reading, plus 城 in its Sino-Japanese reading. Recognising 城 as jō unlocks the names of hundreds of Japanese castles, and recognising 俣 as a fork in the land helps with river-country place names across the country.

Visiting and Context

Futamata Castle lies in Tenryū-ku, in the city of Hamamatsu, Shizuoka Prefecture, on the site of the old Toyoda county of Tōtōmi Province. It is paired with Tobayama Castle, and the two together form the National Historic Site designated in 2018.

For readers of Japanese history, the castle is a useful anchor for two threads. The first is the Sengoku-era contest over the Tōtōmi region, where a small mountain fort could decide control of a river valley. The second is the tragedy of the Tokugawa succession: the death of Matsudaira Nobuyasu in 1579 at this site ties the ruins directly to the inner politics of Ieyasu's rise. A visit to the ruins is a visit to both stories at once.