The Martyr Diomedes (Diomḗdēs) was born in Tarsus in Cilicia, and studied the medical arts. His scientific knowledge did not make him proud, but he retained the piety in which his parents raised him. And since the Lord, the Physician of bodies and souls, “spoke to them about the Kingdom of God, and healed those who had need of healing” (Luke 9:11), so did Diomedes emulate his Lord and God, practicing his medical profession charitably and without charge. Not only did he heal their bodies, he also treated their souls. He proclaimed the saving truth of the Gospel to the sick, and he brought many souls to Christ the Savior.

Divine zeal brought Diomedes as far as Nicaea in Bithynίa. There he healed the sick, and taught and nurtured their faith. When Diocletian began his persecution against the Christians, the activities of Diomedes were reported to the Emperor, who ordered his arrest. But before he could be arrested, God called him to Himself, and the soldiers found him dead. Even though he was dead, they beheaded him in order to prove that Diocletian’s orders had been carried out. Then the soldiers were struck blind. The Emperor commanded them to take the head back and place it with the body. As soon as the soldiers did this, their sight was restored and they believed in Christ.

The Church venerates Saint Diomedes as an Unmercenary Physician and he is mentioned during the Mystery of Holy Unction.

Apolytikion
O Diomedes, as a healer of bodily sickness, you also heal the soul by the word of truth. You received this gift from God, and you always help those who suffer from various diseases. You were radiant with the grace of martyrdom; therefore you preserve those who cry to you: “Glory to Him Who glorified you. Glory to Him Who crowned you. Glory to Him Who, through you, works healings for all.”

Kontakion
You were skilled in the science of healing and wisely chose the assembly of holy contestants; O blessed Diomedes; as a glorious herald of Christ our God, you are the adornment of the Unmercenary Saints, and the protector of those who cry to you: “Be the physician of us your servants, O wise one.”