Supreme Governor of the Church of England Church's assets in England and declared the Church of England as the established church with himself as its head. The Act of Supremacy 1534 confirmed the King's status as having supremacy over the church and required the peers to swear an oath recognising Henry's supremacy. Henry's daughter, Mary I, attempted to restore the English Church's allegiance to the Pope and repealed the Act of Supremacy in 1555. Elizabeth I ascended to the throne in 1558 and the next year Parliament passed the Act of Supremacy 1558 that restored the original act. To placate critics, the Oath of Supremacy which peers
Oath of Supremacy counsellors, Sir Stephen Rice and Justin McCarthy, Viscount Mountcashel. The centrality of the Oath was re-established under the reign of William III and Mary II. Oath of Supremacy The Oath of Supremacy required any person taking public or church office in England to swear allegiance to the monarch as Supreme Governor of the Church of England. Failure to do so was to be treated as treasonable. The Oath of Supremacy was originally imposed by King Henry VIII of England through the Act of Supremacy 1534, but repealed by his daughter, Queen Mary I of England and reinstated under Mary's half-sister,