Tiepolo demonstrated skill as a commander when, during the War of Saint Sabas with Genoa, he defeated the Genoese at the Battle of Acre in 1258.

In 1262, he took part in the peace negotiation between Venice and Prince William of Villehardouin, whose vassal he was for the islands of Skopelos and Skyros,[2] in the aftermath of the War of the Euboeote Succession.

[5] In 1270, a peace treaty was signed with Genoa at Cremona, confirming the Venetian predominance in the Adriatic Sea; however, in that same year a war broke out between Venice and a league of Italian cities including Bologna, Treviso, Verona, Mantua, Ferrara, Cremona, Recanati, and Ancona due to commercial disputes.

After an initial setback in 1271, the Venetians were able to regain the upper hand and the terms of peace were favourable to Venice.

His first wife was, according to conflicting traditions, "either the daughter of the King of Romania or of Bohemund of Brienne, ruler of Rascia".