It is generally accepted[1][2][3] that the gathering never took place and that the purported council documents were forged for political purposes in the 6th century during the schism between Symmachus and Laurentius, who both claimed the Holy See.
[1]The Latin phrase "quia prima sedes non judicatur a quoquam" means roughly "for the occupant of the highest see cannot be judged by anyone",[4] and the anecdote was produced in later centuries as evidence for the doctrine of papal supremacy.
[6] Döllinger summarizes the commonly-received account: Marcellinus is conducted to the temple of Vesta, and there offers sacrifices, in the presence of a crowd of Christian spectators, to Hercules, Jupiter, and Saturn.
After this the bishops remain quietly together in Sinuessa, until Diocletian, upon receiving intelligence of this synod in Persia, sends an order for the execution of many of the three hundred, and this is carried into effect.
[5][4] Vice versa, one scholar writes that during the reign of Antipope Alexander V, Jean Gerson used the story[9] "to prove the legitimacy of a council assembled without the authority of the pope.