The decision of Peter Martyr to identify openly with the Reformed cause was remarkable. He was already 43 and most who courageously joined the Reformed church did so at a younger age. He had a very promising career in the Roman church and left great opportunities behind. But the Lord was to open for him remarkable positions of service and influence for the Reformed faith in the last twenty years of his life.
He served in Strassburg from 1542 to 1547 sharing in the work that Martin Bucer had done there to reform the church. In 1547 he received an invitation from Archbishop of Canterbury, Thomas Cranmer, to teach as a Regis professor at Oxford. There he taught powerfully on the Reformed view of the Lord's Supper, helped Cranmer and others with the 1552 revision of the Book of Common Prayer, and aided Bishop Hooper in the discussion of the use of vestments in the church. When King Edward VI was succeeded on the throne by his half-sister Mary (known to history as "bloody Mary"), Vermigli again had to move to escape Roman Catholic persecution. He returned to Strassburg (1553- 1556) and then settled finally in Zurich where he taught and worked with the distinguished Reformer Heinrich Bullinger. He was widely regarded as one of the greatest Reformed authorities on the Lord's Supper and so was invited to the Colloquy of Poissy in 1561 where he and Theodore Beza defended the Reformed cause before the king and queen mother of France. He also seems to have had a significant influence on Zacharius Ursinus as he was moving from a Lutheran to a Reformed theology. When Vermigli was invited to teach in Heidelberg, he recommended Ursinus in his place. Perhaps Peter Martyr deserves to be called a grandfather of the Heidelberg Catechism.
At the age of 63 his body began to weaken and death approached. He had lived a most remarkable life that had led him to live in many parts of Europe and to know and influence many of the most important figures of his day. His great talents and learning he dedicated to Christ in teaching, preaching and writing (especially on the Lord's Supper and commentaries on the Pentateuch, Judges, 1 and 2 Samuel, 1 and2 Kings, Romans and 1 Corinthians). Excerpts from his writings circulated widely as Loci Communes published in Latin in 1576 and in English in 1583. Josiah Simler who preached a funeral oration for him aptly named him "an ambassador of Jesus Christ, to divers cities and nations.” 
Simler recorded the final hours of Vermigli 's life and his own last words: “And on the day before he died, some of us his friends being present with him, and specially Bullinger among the rest, he lay a certain space meditating with himself; then turning unto us he testified with speech plain enough that he acknowledged life and salvation in Christ alone, who was given by the Father an only favour unto mankind; and this opinion of his he declared and confirmed with reasons and words of scriptures; adding at the last, This is my faith, in this will I die; but they which teach otherwise and draw men any other way. God will destroy them.” These words show the seriousness of his faith and his intense sense of the spiritual conflict of his times. His remarkable life and testimony deserve to be remembered on the 500th anniversary of his birth.