Elias was Patriarch of Aquileia 571–586.
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.
The complete list of the Patriarchs of Grade, Patriarchs of Grado in Venice, and Patriarchs of Venice, since 717 until today