With emperor Otto III's approval, Stephen was crowned as the first Christian king of Hungary on Christmas Day, 1000. Otto III's successor, Emperor Henry II, was Stephen's brother-in-law by Stephen's marriage to Henry's sister Gisela, furthering the friendly relationship between the Empire and Hungary. Under Conrad II, however, relations quickly turned hostile as Conrad pursued a more aggressive policy regarding eastern Europe. Conrad II expelled the Venetian Doge Otto Orseolo, the husband of Stephen's sister Grimelda of Hungary from Venice in 1026. Conrad also persuaded the Bavarians to accept his own infant son, Henry, as their duke in 1027, although Stephen's son, Emeric of Hungary, had a legitimate claim to the Duchy of Bavaria through his mother.