Cyrus was placed on the patriarchal throne in 705 by Emperor Justinian II, as a replacement for the deposed Patriarch Callinicus I. Soon after Justinian's decline and eventual fall in December 711, Kyros was replaced by the new Emperor Philippicus with Patriarch John VI, who shared Philippicus' Monothelite sympathies.
Cyrus was installed as patriarch in 705 by Emperor Justinian II, replacing the ousted Patriarch Callinicus I. Following Justinian's downfall and demise in December 711, Cyrus was succeeded by Emperor Philippicus with Patriarch John VI, who shared Philippicus' sympathies for Monothelitism.