[From the authentic acts of his martyrdom in Baronius and Surius, and most correctly in Ruinart who has published with them the short acts of St. Cassian, p. 312; Tillem. t. iv. p. 575.]
The birthday of the Emperor Maximian Herculeus was celebrated in the year 298 with extraordinary feasting and solemnity. Pompous sacrifices to the Roman gods made a considerable part of this solemnity. Marcellus, a Christian centurion or captain in the legion of Trajan, then posted in Spain, not to defile himself with taking part in those impious abominations, cast away his military belt at the head of his company, declaring aloud that he was a soldier of Jesus Christ, the eternal King. He also threw down his arms and the vine-branch, which was the mark of his post of centurion; for the Roman officers were forbid to strike a soldier with any instrument except a vine-branch, which the centurions usually carried in their lands. The soldiers informed Anastasius Fortunatus, prefect of the legion, by whose order Marcellus was committed to prison. When the festival was over, this judge ordered Marcellus to be brought before him, and asked him what he meant by his late proceedings. Marcellus said, “When you celebrated the emperor’s festival on the 12th before the calends of August (the day on which Maximian had been declared Caesar), I said aloud that I was a Christian, and could serve no other than Jesus Christ, the Son of God.” Fortunatus told him that it was not in his power to connive at his rashness, and that he was obliged to lay his case before the Emperor Maximian and Constantius Caesar. Marcellus was sent under a strong guard to Aurelian Agricolaus, vicar to the prefect of the praetorium, who was then at Tangier, in Africa. Agricolaus asked him whether he had really done as the judge’s letter set forth; and, upon his confessing the fact, the vicar passed sentence of death upon him for desertion and impiety, as he called his action. St. Marcellus was forthwith led to execution and beheaded on the 30th of October. His relics were afterwards translated from Tangier to Leon, in Spain, and are kept in a rich shrine in the chief parish church in that city, of which he is the titular saint.
We justly honour the martyrs, whom God himself honours. Martyrdom is the most heroic act of divine love, and the most perfect and entire sacrifice man can make of himself to God. Of all the goods of this life man has nothing more precious and dear than his life and honour. And what stronger proof can he give of his fidelity to the law of God than to embrace with joy an ignominious and cruel death rather than consent to sin? God proportions his rewards and crowns to the measure of our sufferings and love for him. How great, then, is the glory, how abundant the recompense which attends the martyrs! They rejoiced to see their torments redoubled manifold, because they had before their eyes the incomparably greater increase of grace, divine love, and eternal glory. If we shrink under the least sufferings, it is plain our faith and our idea of everlasting bliss must be very weak, and our love faint and imperfect.
(Taken from Vol. III of “The Lives or the Fathers, Martyrs and Other Principal Saints” by the Rev. Alban Butler.)