Thomas Cranmer was an English archbishop and a key figure in the English Reformation during the 16th century. He served as the Archbishop of Canterbury and played a significant role in the establishment of the Church of England, breaking away from the authority of the Roman Catholic Church. Cranmer is best known for his contributions to the Book of Common Prayer, which standardized Anglican worship. Cranmer's theological ideas emphasized the importance of scripture and faith, influencing the development of Anglicanism. He faced persecution for his beliefs, particularly under the reign of Queen Mary I, who sought to restore Catholicism in England. Ultimately, Cranmer was executed in 1556 for heresy, but his legacy endures in the Anglican tradition.