Protestantism is a branch of Christianity that follows the theological tenets of the Protestant Reformation: a movement that began seeking to reform the Catholic Church from within in the 16th century against what its followers perceived to be growing errors, abuses, and discrepancies within it. The political separation of the Church of England from the pope under King Henry VIII began Anglicanism, bringing England and Wales into this broad Reformation movement, under the leadership of reformer Thomas Cranmer, the then Archbishop of Canterbury, whose work forged Anglican doctrine and identity.