Siege of Iwaya
- Shimazu Yoshihiro (50,000) vs. Takahashi Shigetane (760)
- Japanese: 岩屋城の戦い (Iwaya jou no tatakai), 岩屋城攻め (Iwaya jou seme)
With the defeat of the Ryûzôji clan at Okita-nawate in 1584, the Shimazu returned their full attention to their push into Ôtomo clan territory. Iwaya was located in Daizaifu, in the south of Chikuzen province, and was controlled by one of the pillars of the Ôtomo house, Takahashi Shigetane (Jôun) and his son Tachibana Muneshige, with a force of some 760 men. Jôun rejected the Shimazu calls for their capitulation, believing that reinforcements from Toyotomi Hideyoshi and the Môri clan would arrive soon.
After holding out for two weeks against enormous odds, Shigetane, aware of the futility of further resistance, committed suicide. When the Shimazu heard of his end, they are said to have prayed for his spirit, so impressed were they by his bravery. In the end, the defenders of the castle were destroyed entirely; however, the attackers suffered considerable losses as well. Hesitant to get involved in a lengthy engagement, the Shimazu then left it up to their newly acquired retainers of northern Kyushu to besiege Muneshige's Tachibana castle for him.
This siege caused the Shimazu invasion of Bungo province to be delayed; Toyotomi Hideyoshi would arrive the following year and seize Kyushu for himself before the Shimazu were able to complete their own conquest of the island.