Hermagoras of Aquileia was the first archbishop of Aquileia, according to legend chosen by St Mark, and invested by St Peter in Rome.
Venice had its own church organisation from the 800s, but the origins go back to before the Lombard invasion, and events in the Eastern Roman Empire.
This document is the earliest description of the translation of St Mark to Venice in 827–828, and also of early Venice. This is a translation by René Seindal.