In the 1560s, Philip II of Spain was faced with increasing religious disturbances as Protestantism gained adherents in his domains in the Low Countries. As a defender of the Catholic Church, he sought to suppress the rising Protestant movement in his territories, which eventually exploded into open rebellion in 1566. Meanwhile, relations with the regime of Elizabeth I of England continued to deteriorate, following her restoration of royal supremacy over the Church of England through the Act of Supremacy in 1559; this had been first instituted by her father Henry VIII and rescinded by her sister Mary I, Philip's wife. The Act was considered by Catholics as a usurpation of papal authority. Calls by leading English Protestants to support the Protestant Dutch rebels against Philip increased tensions further as did the Catholic-Protestant disturbances in France, which saw both sides supporting the opposing French factions.