Dictionary of Christian Biography and Literature to the End of the Sixth Century/Antipopes
Antipopes, claimants to the popedom in opposition to the lawful popes. There were seven such during the first six centuries, some owing their elevation to the existence of conflicting parties at Rome, others intruded into the see by the civil power. A fuller account of them, with the authorities, is given under their respective names—viz. Novatianus; Felix; Ursinus (or Ursicinus); Eulalius; Laurentius; Dioscorus; Vigilius.