Constantine II, Antipope

Antipope Constantine II (d. 768) was an antipope in 767 and 768. In spring 768 he was deposed and killed by Lombards, when prisoner in the monastery of San Saba.

Antipope Constantine II in "Islands in the Sea"
Pope Constantine II sent a delegation in AD 769 to a heathen Bulgar Khan named Telerikh at the latter's request. The emissaries were Fathers Niketas and Theodore and a monk named Paul. The purpose was to attempt to convert Telerikh and his people to Christianity.