St. Cosmas and St. Damian, patron saints of medicine, grafting the leg of an Ethiopian gladiator onto a Christian bell-tower keeper. Oil painting attributed to the Master of Los Balbases, c. 1495. Cosmas and Damian were physician brothers who practiced in Aleppo (modern-day Syria). They were martyred in the 4th century AD. The most famous legend surrounding these saints concerns a bell-tower keeper with a gangrenous leg who prayed at the Church of St. Cosmas and Damian in Rome. In a miraculous operation, the man's leg was amputated and successfully replaced with the leg of an Ethiopian gladiator who had recently died. The subject became popular with artists.