During the pontificate of Pope Adrian II, Anastasius became involved in serious difficulties when, in 868, his brother Eleutherius forcibly carried off the daughter of the Pope and soon afterwards killed her and her mother. Eleutherius was executed and Anastasius, who was regarded as the instigator of the murder, was punished by excommunication and deposition. He lived at the Imperial court and sought by the intervention of the Emperor to exculpate himself before the Pope. Joseph Hergenröther maintains that the "bibliothecarius" and the presbyter Anastasius (the antipope) were one and the same person, and weaves all the statements concerning the latter into the biography of Anastasius, while Joseph Langen considers them different persons. In August, 879, Zacharias of Anagni appears as Head of archives of the Roman Church, so Anastasius must have died shortly before this date.