 Thereby Michael accepted to become a vassal of Venice, holding his lands in fief from Venice as confirmed in a charter issued by Doge Pietro Ziani ().Michael granted the Venetians extensive trading privileges and tax exemptions, just as they had enjoyed under the chrysobulls of Emperor Manuel I Komnenos (), promised to expedite the grain exports to Venice, and to assist in any shipwreck of a Venetian vessel off the Epirote coast.In addition, as a sign of his vassalage he would pay to the Venetian duke of Dyrrhachium an annual tribute of 42 "litrai" of gold "hyperpyra" in two instalments, and send annually a rich brocade for the altar of St. Mark's Basilica and one for the Doge.