Ieyasu Tokugawa was born on January 31, 1543 in Okazaki, Aichi, Japan. He was known in early childhood as Takechiyo. Ieyasu was born the eldest son of Hirotada Matsudaira, Lord of Okazaki Castle in Mikawa (Aichi Prefecture).His mother was called Denzuin, daughter of Tadamasa Mizuno. His mother and father were step-siblings. They were just 17 and 15 years old, respectively, when Ieyasu was born. When he was two years old his mother was divorced due to discord between the Matsudaira and Mizuno families. As both husband and wife remarried and both went on to have further children, Ieyasu eventually had 11 half-brothers and sisters.