Vratislaus II of Bohemia
Vladislav I was a son of Vratislaus II of Bohemia by his second wife Svatava, a daughter of Casimir I of Poland. Together with his cousin Svatopluk, Vladislav expelled his brother Bořivoj II from Bohemia in 1107. In 1109, Svatopluk was killed during a campaign in Poland, and Vladislav I succeeded him as Duke of Bohemia. Bořivoj II returned from exile with the support of Prince Bolesław III Wrymouth of Poland, but was defeated and imprisoned by Vladislav in 1110.