[1] During the pontificate of Pope Nicholas I (858–867) Anastasius was abbot of Santa Maria in Trastevere on the farther side of the Tiber.
[citation needed] The successor of Nicholas, Pope Adrian II (867–872), appointed Anastasius bibliothecarius (Head of archives) of the Roman Church, an important office at the Lateran Palace that gave him further influence at the papal court.
The successor of Adrian II, Pope John VIII (872–882), also esteemed Anastasius, confirmed him in the office of librarian, entrusted important affairs to him, and encouraged him to further literary work.
[5] In August, 879, Zacharias of Anagni appears as Head of archives of the Roman Church, so Anastasius must have died shortly before this date.
[6] The attribution to Anastasius of the ancient Latin translation of the Acts of the Third Council of Constantinople has been proved to be wrong on manuscript evidence by Rudolph Riedinger.
[citation needed] He also compiled a historical work, "Chronographia tripartita", from the Greek writings of Theophanes, Nicephorus, and George Syncellus, and made a collection of documents concerning the affairs of Pope Honorius I.