The siege of Nagakubo (é·窪åÂÂ) was a battle of Japan's Sengoku period. It took place in 1543 as part of Takeda Shingen's bid to control Shinano Province, Japan. He took the castle of his former ally, Oi Sadataka, who had deserted him to ally with Murakami Yoshikiyo. Oi was sent to Takeda's home city of Kà Âfu as a prisoner, where he was then killed.