Wenceslaus III was the 7th King and the 1st Emperor, his wife Viola of Cieszyn was from the House of Piast and was related to Wladyslaw I the Elbow-High. Wenceslaus's sister Anne married Henry of Carinthia which helped him to become regent to Wenceslaus's sons Premysl Otakar III and Borivoj III. Through marriage Premyslids are related to killed of both Wenceslaus and Henry, Conrad of Bolštejn, who had daughter Margaret who married Wenceslaus's last son Vladislaus. The kingship then went to their first son Vladislaus III. He also had other siblings including John who inherited the duchy of Warsaw from him when he became king and Margaret who became the duchess of Pilsen. Vladislaus then married Mary of England, daughter of Edward IV, making his children related to John I of Luxembourg and Andronikos III Palaiologos. These children were Borivoj IV and Vratislaus of Pilsen.