Saints Cosmas and Damian were twins born to Christian parents in Arabia in the third century. Living in the region around the border between modern-day Turkey and Syria. They were physicians. They were renowned for their skill and their refusal to charge for their consultation.
Their charity and Christian witness made many people come to the faith of Christianity in the Christian communities of Asia Minor. Therefore, when the Diocletian persecutions began in the latter half of the third century they were some of the first to be sought out for execution.
In 287, they were captured and ordered to deny their faith in Christ. They refused and underwent a series of tortures, including the Crucifixion, from which, miraculously, they remained unscathed. The torturers, weary of what they realized was the impossible task of forcing apostasy from their mouths, finally beheaded them both.
They are invoked in the Canon of the Mass and the Litany of Saints.