Complex sentence: But when both his opponent, Frederick I, and Gustav Vasa, who joined the Reformation, became Lutherans in 1530 Christian reconverted to Roman Catholic Church and thus reconciled with the Emperor.
Split into simpler sentences: But when both his opponent, Frederick I, and Gustav Vasa, who joined the Reformation, became Lutherans. In 1530 Christian reconverted to Roman Catholic Church and thus reconciled with the Emperor.