Okazaki, Aichi
The Aoyama clan were provincial lords of Dōdo village, Nukata District in Mikawa Province (present Okazaki, Aichi). Aoyama Tadakado, Tadanari's father, served both Matsudaira Hirotada and Tokugawa Ieyasu, and thus Tadanari served near Ieyasu since he was young. In 1572, his father died in battle with Takeda Shingen and Tadanari inherited the estate.