Battle of Okitanawate
- Ryûzôji Takanobu (25,000) vs. Shimazu Iehisa (under the command of Shimazu Yoshihisa) (2,000)/Arima Harunobu (1,000)
- Japanese: 沖田畷の戦い (Okitanawate no tatakai)
The 1584 Battle of Okitanawate was fought in the Shimabara area of Hizen province (today, Nagasaki prefecture), between forces of the Shimazu and Ryûzôji clans. It ended in Shimazu victory, with the Ryûzôji submitting to becoming Shimazu vassals, and the Shimazu coming one step closer to controlling all of Kyushu.
As Ryûzôji Takanobu gradually expanded out from his base at Saga, his territory eventually came to border that of the expanding Shimazu. Shimazu Iehisa (younger brother of Shimazu Yoshihisa) called for aid from the Arima clan of Hizen, and the Akahoshi clan of Higo, and crossed over to the Shimabara peninsula. Seeking to crush both the troublesome Shimazu and Arima, and to defend his hold on Hizen province, Takanobu then led a force to meet them. While the Ryûzôji had never quite recovered from a defeat at the hands of the Ôtomo in 1569 (nearly twenty years earlier), Takanobu still had some fine leaders and a large army. The Ryûzôji forces at Okitanawate possessed more than ten times the numbers of their opponents.
Yet, at Okitanawate, the confident Takanobu was to suffer a fatal setback. The two main Ryûzôji columns were quickly stalled by cannon fire from the small but well-armed Arima navy and by Shimazu forces which surprised them with an attack on their flank. In the growing confusion, a band of Shimazu swordsmen raced for Takanobu's position; Takanobu (like Imagawa Yoshimoto at Okehazama) believed that a fight had broken out among his own men. Takanobu was killed and the news generated a general panic within the Ryûzôji ranks despite the best efforts of Nabeshima Naoshige to maintain order. The Ryûzôji at length fled the field and Takanobu's son Masaie was later made to submit to the Shimazu.