A breach with Rome took place during the first half of the fifteenth century as a consequence of the reform movement begun by Jan Hus. After Hus was burned at the stake in Constance in 1415, his legacy became a lasting aspect of the national heritage. It was reinforced in the middle of the sixteenth century by the attempts of Ferdinand I, the Holy Roman emperor and Bohemian king, to bring the population back under the influence of the Roman Catholic Church. After the army of the Bohemian estates was defeated by Ferdinand II in the Battle of White Mountain in 1620, Catholicism and Hapsburg rule tended to be equated as symbols of foreign oppression.