Martin was the last Pope to be venerated as a martyr. Born in the Italian town of Todi in Umbria, as a young man he rose rapidly in the church, and served his predecessor Pope Theodore I as papal nuncio to Constantinople.
At this time, there was a growing belief among Christians that Jesus was purely divine, without the will of a human being. The Emperor Constantine was one of the main supporters of this idea. As soon as Martin became Pope he called a council to condemn this notion. The Emperor Constantine was furious and had the Pope arrested. For three months, Martin was treated very cruelly in prison. At a trial at which he was not allowed to defend himself, he was sentenced to death.
The dying Patriarch of Constantinople, pleaded to the Emperor to spare him. Martin was banished to Khersonesus in the Crimea where he died in 656.