Ōta Sukemasa

Ōta Sukemasa (1522-1591) was a Sengoku-period military commander. A descendant of Ōta Dōkan, the builder of Edo Castle, he based himself at Iwatsuki Castle in Musashi Province and fought a long struggle against the Late Hōjō clan.

Origins and the Succession at Iwatsuki

He was born the second son of Ōta Sukeyori, a retainer of the Ōgigayatsu Uesugi. In 1547, following his elder brother's death, he took the headship of Iwatsuki Castle by force. Rather than inheriting the position in orderly succession, he seized it through his own power — an early sign of the independent streak that would run through his career.

Conflict with the Late Hōjō

He initially submitted to Hōjō Ujiyasu, but in response to Uesugi Kenshin's invasion of the Kantō in 1560 he broke decisively with the Hōjō and turned openly hostile. From then on he remained one of the central figures of anti-Hōjō resistance in the Kantō, sustaining the conflict over many years.

The War Dogs

What most distinguishes Sukemasa's reputation is the account of his use of trained dogs for communication. According to the *Kōyō Gunkan*, he tied bamboo tubes containing letters to the necks of dogs and released them from the castle, maintaining contact with a separate stronghold at a distance. Through this method — known as the "rotation of the Sanraku dogs" — he is said to have preserved the flow of information even under siege and repelled Hōjō attacks. It is a frequently cited episode in discussions of intelligence and communication in Sengoku warfare.

The Loss of Iwatsuki and Taking the Tonsure

In 1564 his son Ujisuke seized Iwatsuki Castle and surrendered it to the Hōjō, driving Sukemasa out — the loss of his home base in the bitterest possible form, at the hands of his own son. After a failed attempt to retake the castle in 1565, Sukemasa took the tonsure and adopted the religious name Sanrakusai Dōyo.

Service to the Satake and Final Years

He subsequently passed through the Utsunomiya clan of Shimotsuke before entering the service of Satake Yoshishige of Hitachi Province, becoming lord of Katano Castle. That he held to his anti-Hōjō position even after losing his own domain, continuing to fight while sheltered by other houses, marks the consistency of his career. He died of illness at Katano Castle in 1591 at the age of 70 — the year after the Late Hōjō were destroyed in the Odawara Campaign.