A young Gaul who refused to salute an idol carried in procession, he was beheaded to the encouragement of his mother.
His passion, written later but attached to a very old cult, has him born into a noble family of Augustodunum — Autun — in the second century. On a feast day the statue of Cybele was carried in procession through the town; he remained standing and refused to bow. Arrested, he answered the judge Heraclius that he did not know these gods and would not worship them, and the magistrate condemned him to death. The scene that has remained famous is that of his mother who, from the top of the rampart, saw him led to execution and cried to him not to fear a death that leads to life. He was beheaded outside the walls. Gregory of Tours attests his cult in the sixth century, and the abbey of Saint-Symphorien at Autun became one of the major sanctuaries of Christian Burgundy. He appears in the Roman martyrology and his feast falls on 22 August.
Shown as a young man holding the martyr's palm, sometimes kneeling at the foot of the rampart from which his mother urges him on.