Page "Monothelitism" Paragraph 8

Patriarch Sergius I of Constantinople was the driving force behind this doctrine, with the full blessing of the Emperor Heraclius.

Coming to the imperial throne in 610, the patriarch had long since converted the emperor to the new doctrine, as by 622, Heraclius had communicated with Bishop Paul of Armenia where the emperor asserted that the energy, or the active force, of Christ was single.

This doctrine of Monoenergism was the precursor of Monotheletism.