St. Thomas More was the most famous victim of King Henry VIII's persecution of Catholics who refused to accept royal supremacy over the Church in England.
The son of a lawyer and judge, St. Thomas studied law and also considered becoming a priest, but instead pursued a legal career and marriage. He became well known for his intelligence and integrity. His reputation as a man of letters and learning was definitively established with the publication of his Latin classic, Utopia. In 1529, Henry VIII promoted him to a series of public offices, including that of the king's Lord Chancellor, a post at which St. Thomas excelled because of his fairness and integrity.
After some hesitation, St. Thomas accepted the king's new title, "Protector and Supreme Head of the Church of England," but with St. John Fisher's qualification, "so far as the law of Christ allows." But in 1532, St. Thomas resigned the chancellorship, concerned about the king's real intentions.
In 1534, the Act of Succession required all of the king's subjects to recognize the offspring of his second marriage to Anne Boleyn as successors to the throne -- and to assent to the nullity of the king's first marriage to Catherine of Aragon and the validity of his second marrriage. St. Thomas could have assented to the first proposition, but not to the second and third, especially since the pope had just declared the validity of the first marriage. For refusing to take the oath, St. Thomas was imprisoned in the Tower of London on April 13, 1534. He forfeited all his lands and his family shared his poverty.
St. Thomas' trial was held on July 1. In his own defense he argued that his indictment was based on an act of Parliament that was against the laws of God and the Church, that no temporal prince can declare himself superior to the pope in spiritual matters, and that the king's new title was contrary to his coronation oath. Nevertheless, St. Thomas was condemned to death, on perjured testimony, at which point he expressed the hope that he and his judges would "hereafter in heaven all meet merrily together, to our everlasting salvation."
St. Thomas was beheaded on Tower Hill on July 6. His last words were that he was dying for the faith of the Holy Catholic Church and was "the king's good servant, but God's first."
(Source: Lives of the Saints, Richard P. McBrien)