Bessho Nagaharu (別所 長治, 1558 – February 2, 1580) was a Japanese daimyō of the Sengoku period.
Nagaharu almost decided to ally with the Oda clan, but after hearing that the low-born general Hashiba Hideyoshi, whom he did not respect, was leading the troops, he revolted and instead allied himself with Hatano Hideharu of Tanba province.
Nagaharu took a stand at Miki Castle, and was besieged by Hideyoshi's troops on the orders of Nobunaga.
The Siege of Miki[1] did not go well for Hideyoshi, and with a revolt by Araki Murashige and the help of the Mōri clan, Nagaharu successfully repelled the Oda force.
This led to a rapid depletion of food, and in 1580, with no hope of another reinforcement from Mōri clan, Nagaharu committed seppuku in exchange for the lives of the troops in Miki Castle.