He was born in Cappadocia, on the borders of Armenia Minor, in the third century AD. Since childhood he devoted himself to the study of Literature, Physics and Medicine, achieved brilliant results and became famous and beloved in his homeland. For these merits, but especially for his virtues of purity, charity and humility, the clergy and the people of Sebastea acclaimed him Bishop of the city.
Biagio accepted even if he knew that in those days Bishops often became destined victims to sacrifice. Under Diocletian, the Emperor's minister Agricola started a severe persecution against Christians; Biagio visited and encouraged his people, comforting them in prison. On Diocletian's death his successor Constantine seemed to bring peace, but the respite was short due to a dispute between the emperor and his brother in law Licinius who restarted the persecution against Christians in Cappadocia.
The people of Sebastea, concerned about the fate of their Bishop, convinced Biagio to retreat to Monte Argaeus in a deep cave where he lived for some time in solitude, prayer and contemplation. One day soldiers came to his refuge and were amazed at Biagio absorbed in prayer and the beasts of the forest around him in an attitude of reverence. Once back in the city they reported their extraordinary meeting to Agricola, who, realizing that the hermit was certainly the Bishop Biagio, commanded his soldiers to take him immediately nefore him.
Biagio received them meekly and followed them walking towards the city as to a triumph. The news of his capture spread quickly and Christians crowded to its passage. He blessed everyone and the sick were healed. Once before Agricola, Biagio firmly expressed his Christian faith, and at first was severely beaten. During the second meeting, Agricola asked him to worship pagan gods and after Biagio's refusal he ordered a cruel torture: he was suspended from a beam and his flesh was torn with iron carding combs, blood flowing at his feet. Even his torturers were moved, and seven women who had demonstrated their compassion were martyred instantly.
The serenity and strength of Biagio in bearing his torture doubled the wrath of Agricola who ordered him to be thrown into a lake with a heavy stone around his neck. But at the bishop's sign of cross the water became compact ground and he walked on the lake returning to the shore. The judge then accused him of sorcery and sentenced him to be beheaded. He was led out of the city to the execution place, but before his death he thanked God for the martyrdom asking Him to listen to the prayers of those who begged to be healed of throat diseases of and every other illness of soul and body.
A voice was heard from above which ensured that his prayer had been answered in heaven and then Biagio was killed, along with two young boys, the sons of one of the seven women martyred the day before, who wanted to follow their mother to witness their faith. It was the 3rd February in the year 319 AD. During the night, a pious Christian woman of Sebastea, Elisa, buried Biagio's body in a place where later a Cathedral was built, which became a site of miracles and a destination of pilgrimages.
In 732 a part of his mortal remains were placed in a marble urn and shipped to Rome. A storm stopped the ship at Maratea, where the faithful greeted the casket containing the relics - the "sacred chest" and other parts of the body - and kept them in a Basilica, on Mount San Biagio. The chapel with the relics was then placed under the protection of the Royal Clergy by King Philip IV Habsburg, with a royal letter dated December 23, 1629 and since then it has been popularly known by the name of "Royal Chapel".
A large number of places boast of having a fragment of the body of the saint - this is due to the ancient custom of dissecting the bodies of saints and distribute parts to meet the demands of the faithful.