Hamamatsu Domain
Aoyama Tadashige was the third son of Aoyama Munetoshi, the daimyō of Komoro Domain and was born in Komoro, Shinano Province. On August 5, 1683, he was adopted by his sickly elder brother Aoyama Tadao, at the time daimyō of Hamamatsu Domain (Tōtōmi Province). He became 5th head of the Aoyama clan and daimyō of Hamamatsu on his brother's death in 1685.