Azai Nagamasa (浅井 長政, 1545 – 26 September 1573) was a Japanese daimyō of the Sengoku period known as the brother-in-law and enemy of Oda Nobunaga.[1] Nagamasa was head of the Azai clan seated at Odani Castle in northern Ōmi Province and married Nobunaga's sister Oichi in 1564, fathering her three daughters – Yodo-dono, Ohatsu, and Oeyo – who became prominent figures in their own right.[1]