On September 26 the Church honors Sts. Cosmas and Damian, twin brothers and physicians who practised medicine without fee — the anargyroi, "the silverless," as the Greek Church calls them — and were martyred for their faith. They are invoked in the Roman Canon at every Mass and in the Litany of the Saints, and they are patrons of physicians, surgeons, pharmacists, and dentists.
Cosmas and Damian were born in Arabia in the third century and practised medicine and surgery in the seaport of Aegeae, in the Roman province of Cilicia — modern Yumurtalık in southern Turkey. During the Diocletian persecution they were arrested by Lysias, the prefect of Cilicia, tortured — hung on a cross, stoned, shot by arrows — and finally beheaded, together with their younger brothers Anthimus, Leontius, and Euprepius. The traditional date of their martyrdom is around 287.
Their cult spread rapidly across the Christian world. The most famous shrine is the Basilica of Santi Cosma e Damiano in Rome, built by Pope Felix IV around 526-530 in the ancient Forum of Vespasian, converting the former Library of Peace into a church. Its 6th-century apse mosaic — Christ flanked by the two brother-physicians in white robes, with Pope Felix offering a model of the church — is one of the masterpieces of early Christian art in Rome. The basilica stands at the edge of the Roman Forum, a short walk from the Colosseum, and is an active place of worship.
Their relics were originally buried at Cyrrhus in Syria; Justinian I brought relics to Constantinople and built a church there in their honour. Skulls attributed to them are venerated at the Convent of Las Descalzas Reales in Madrid and at St. Michael's Church in Munich. The most famous medieval legend of the saints is the Miracle of the Black Leg — a posthumous nocturnal transplant of a deceased Ethiopian man's leg onto a cancerous verger in Rome, recorded in the Golden Legend and depicted in paintings throughout Europe, the earliest miraculous amputation-and-transplant story in Christian tradition.
The 1969 calendar reform moved the feast from September 27 to September 26, because September 27 is the dies natalis of St. Vincent de Paul. In the Canadian calendar, the feast is kept on September 25, because September 26 is occupied by the Canadian Martyrs.
