Istria, March of

Nikephoros I and Charles I had tried to settle their imperial boundaries in 803.

A first treaty had indeed been prepared and sent to the East by Charles, who had started talks with Empress Irene.

The text, however, was never ratified by Nikephoros, as the Royal Frankish Annals, and Charles in a surviving document, explicitly state.

The Franks had already subdued the March of Istria, and after overturning the Avar khaganate, they claimed the rich Pannonian plain and the Dalmatian coast; following these events, Dalmatian Croatia, located in what is nominally Roman Dalmatia, had peacefully accepted limited Frankish overlordship.

Charles from 806 wages a generally successful war against Constantinople for control of the northern Adriatic sea regions of Dalmatia and Venetia.

The contest over the Istrian bishoprics, fomented by Charlemagne and by Lothair I between the patriarchs of Grado and Aquileia, continues, while Giustiniano works to increase the prestige of the Venetian church itself.

Traditionally, Venice had first been evangelized by Saint Mark himself and many Venetians have made the pilgrimage to Mark's grave in Alexandria, Egypt.

According to tradition, Giustiniano ordered merchants, Buono di Malamocco and Rustico di Torcello, to corrupt the Alexandrine monks who guarded the body of the evangelist and steal it away secretly to Venice.

The Venetian ship, with the corpse hidden among some pork, slipped through customs and sailed into Venice on January 31, 828 with the body of Saint Mark.

Giustiniano decides to build a ducal chapel dedicated to Saint Mark to house his remains: the first Basilica di San Marco in Venice.

The patriarchal seat is also moved to Rialto.

With an evangelist on its territory, Venice acquires a status almost equal to that of Rome itself.