Cromwell, Earl of Essex. Thomas Cromwell, (c. 1485 - 28 July 1540) was an English lawyer and statesman who served as chief minister to King Henry VIII from 1534 to 1540, when he was beheaded on orders of the king. Cromwell was one of the strongest and most powerful proponents of the English Reformation. He helped to engineer an annulment of the king's marriage to Catherine of Aragon so that Henry could lawfully marry Anne Boleyn. During his rise to power, Cromwell made many enemies, including his former ally Anne Boleyn. He played a prominent role in her downfall.