Thomas Cranmer (2 July 1489 – 21 March 1556) was a leader of the English Reformation and Archbishop of Canterbury during the reigns of Henry VIII, Edward VI and, for a short time, Mary I. He helped build the case for the annulment of Henry's marriage to Catherine of Aragon, which was one of the causes of the separation of the English Church from union with the Holy See. Along with Thomas Cromwell, he supported the principle of royal supremacy, in which the king was considered sovereign over the Church within his realm. During Cranmer's tenure as Archbishop of Canterbury, he was responsible for establishing the first doctrinal and liturgical structures of the reformed Church of England. Under Henry's rule, Cranmer did not make many radical changes in the Church, due to power struggles between religious conservatives and reformers. He published the first officially authorised vernacular service, the Exhortation and Litany.When Edward came to the throne, Cranmer was able to promote major reforms. He wrote and compiled the first two editions of the Book of Common Prayer, a complete liturgy for the English Church. With the assistance of several Continental reformers to whom he gave refuge, he changed doctrine or discipline in areas such as the Eucharist, clerical celibacy, the role of images in places of worship, and the veneration of saints. Cranmer promulgated the new doctrines through the Prayer Book, the Homilies and other publications. After the accession of the Catholic Mary I, Cranmer was put on trial for treason and heresy. Imprisoned for over two years and under pressure from Church authorities, he made several recantations and apparently reconciled himself with the Catholic Church. While this would have normally absolved him, Mary wanted him executed, and, on the day of his execution, he withdrew his recantations, to die a heretic to Catholics and a martyr for the principles of the English Reformation. Cranmer's death was immortalised in Foxe's Book of Martyrs and his legacy lives on within the Church of England through the Book of Common Prayer and the Thirty-Nine Articles, an Anglican statement of faith derived from his work.

On 13 November 1553 Cranmer and four others were brought to trial for treason, found guilty, and condemned to death. Numerous witnesses testified that Cranmer had encouraged heresy and had written heretical works. Throughout February 1554 Jane Grey and other rebels were executed. It was now time to deal with the religious leaders of the reformation, and so on 8 March 1554 the Privy Council ordered Cranmer, Ridley, and Latimer to be transferred to Bocardo prison in Oxford to await a second trial for heresy. During this time Cranmer was able to smuggle out a letter to Martyr who had fled to Strasbourg, the last surviving document written in his own hand. He stated that the desperate situation of the church was proof that it will eventually be delivered and wrote, "I pray that God may grant that we may endure to the end!" Cranmer remained isolated in Bocardo prison for seventeen months before the trial started on 12 September 1555. Although it took place in England, the trial was under papal jurisdiction and the final verdict would come from Rome. Under interrogation, Cranmer admitted to every fact that was placed before him, but he denied any treachery, disobedience, or heresy. The trial of Latimer and Ridley started shortly after Cranmer's but their verdicts came almost immediately and they were burnt at the stake on 16 October. Cranmer was taken to a tower to watch the proceedings. On 4 December, Rome decided Cranmer's fate by depriving him of the archbishopric and giving permission to the secular authorities to carry out their sentence.  In his final days Cranmer's circumstances changed, which led to several recantations. On 11 December, Cranmer was taken out of Bocardo and placed in the house of the Dean of Christ Church. This new environment was very different from that of his two years in prison. He was in an academic community and treated as a guest. Approached by a Dominican friar, Juan de Villagarcía, he debated the issues of papal supremacy and purgatory. In his first four recantations, produced between the end of January and mid-February, Cranmer submitted himself to the authority of the king and queen and recognised the pope as head of the church. On 14 February 1556, he was degraded from holy orders and returned to Bocardo. He had conceded very little and Edmund Bonner was not satisfied with these admissions. On 24 February a writ was issued to the mayor of Oxford and the date of Cranmer's execution was set for 7 March. Two days after the writ was issued, a fifth statement, the first which could be called a true recantation, was issued. Cranmer repudiated all Lutheran and Zwinglian theology, fully accepted Catholic theology including papal supremacy and transubstantiation, and stated that there was no salvation outside the Catholic Church. He announced his joy of returning to the Catholic faith, asked for and received sacramental absolution, and participated in the mass. Cranmer's burning was postponed, and under normal practice of canon law he should have been absolved. Mary decided that no further postponement was possible. His last recantation was issued on 18 March. It was a sign of a broken man, a sweeping confession of sin. Despite the stipulation in canon law that recanting heretics be reprieved, Mary was determined to make an example of Cranmer, arguing that "his iniquity and obstinacy was so great against God and your Grace that your clemency and mercy could have no place with him", and pressed ahead with his execution. Cranmer was told that he would be able to make a final recantation but this time in public during a service at the University Church. He wrote and submitted the speech in advance and it was published after his death. At the pulpit on the day of his execution, he opened with a prayer and an exhortation to obey the king and queen, but he ended his sermon totally unexpectedly, deviating from the prepared script. He renounced the recantations that he had written or signed with his own hand since his degradation and he stated that, in consequence, his hand would be punished by being burnt first. He then said, "And as for the pope, I refuse him, as Christ's enemy, and Antichrist with all his false doctrine." He was pulled from the pulpit and taken to where Latimer and Ridley had been burnt six months before. As the flames drew around him, he fulfilled his promise by placing his right hand into the heart of the fire while saying "that unworthy hand". His dying words were, "Lord Jesus, receive my spirit ...; I see the heavens open and Jesus standing at the right hand of God."