Olympius (Ancient Greek: Ολύμπιος, romanized: Olúmpios; died 652) was Exarch of Ravenna from 649 until his death in 652.
[1] In 649, according to the Liber Pontificalis, the Byzantine emperor Constans II ordered Olympius to arrest Pope Martin I on the grounds that the pope's election had not been submitted to the emperor for approval.
Constans was upset with Martin's condemnation of the Monothelite heresy; he feared that it would resurrect the religious conflict that had plagued the empire.
Olympius attempted to gain the support of the citizenry of Rome, as well as the bishops; he also allegedly considered ordering the assassination of Martin.
Eventually, Olympius decided to switch his allegiance and sided with the Pope, simultaneously declaring himself emperor.