Pantaleon Nicomediensis, a physician, was the son of the pagan Eustorgius and his Christian wife Eubule. Pantaleon was attached to the person of the Emperor Maximian, but having been converted to Christianity by the priest Hermolaus, he was denounced to the emperor, who ordered him to be subjected to torture and burned with torches, during which torments he was comforted by an apparition of Our Lord. His martyrdom ended by a stroke of the sword at the royal palace in Nicomedia in 303 AD. A church was dedicated to him at Constantinople at an early age but by the sixth century it was so old and out of repair that Justinian completely rebuilt it in 532 AD.
Dom Prosper Guéranger:
The East celebrates today one of her great martyrs who was both a healer of bodies and a conqueror of souls. His name, which recalls the strength of the lion, was changed by heaven at the time of his death into Panteleemon, or all-merciful: a happy presage of the gracious blessings our Lord would afterwards bestow on the Earth through His means. The various translations and the diffusion of his sacred relics in our West have made his cultus widespread, together with his renown as a friend in need, which has caused him to be ranked among the saints called “helpers.”
“What is stronger than a lion, and what is sweeter than honey?” (Judges xiv. 18). Greater than Samson, you, O Martyr, did in your own person propose and solve the riddle: Out of the strong came forth sweetness (Judges xiv. 14) O lion, who followed so fearlessly the Lion of Judah, you imitated his ineffable gentleness, and as He deserved to be called eternally the Lamb, so did He will His Divine Mercy to shine forth in the everlasting heavenly name into which He changed your earthly name. Justify that title more and more for the honour of Him who gave it to you. Be merciful to those who call on you: to the sufferers whom a weary consumption brings daily nearer to the tomb; to physicians, who, like you, spend themselves in the care of their brethren: assist them in giving relief to physical suffering, in restoring corporal health; teach them still better to heal moral wounds, and lead souls to salvation.Also on this day according to the ROMAN MARTYROLOGY:
In Nicomedia, St. Hermolaus, priest, by whose instructions the blessed Pantaleon was converted to the faith.
Also the Saints Hermippus and Hermocrates, brothers. After many sufferings borne for the confession of Christ, they were condemned to capital punishment by the same Maximian.
At Nola, the holy martyrs Felix, Julia and Jucunda.
At Biseglia, in Apulia, the holy martyrs Maurus, bishop, Pantaleemon and Sergius, who suffered under Trajan.
In the country of the Homerites (Arabia), the commemoration of the holy martyrs who were delivered to the flames for faith of Christ under the tyrant Dunaan.
At Cordova in Spain, during the persecution of the Arabs, the holy martyrs George, deacon, Felix, Aurelius, Natalia and Liliosa.
At Ephesus, the birthday of the seven holy sleepers, Maximian, Malchus, Martinian, Denis, John, Serapion and Constantine.
At Auxerre, the demise of blessed Ætherius, bishop and confessor.
At Constantinople, blessed Anthusa, a virgin. Under Constantine Copronymus, after being scourged and banished, she rested in the Lord.
And in other places, many other holy martyrs, confessors and virgins.
Thanks be to God.