Ottokar I of Bohemia
Louis married the widowed Ludmilla of Bohemia in 1204 to gain the alliance of her uncle King Ottokar I of Bohemia. This also gave him claim to the lands of Albert III of Bogen (brother-in-law of King Ottokar I), if at least not directly. That same year, the Margraviate of Vohburg passed to Louis as well.