Mordini's acceptance into the centrist mainstream was confirmed during 1866 when he was accepted the proposal from "prime minister" Bettino Ricasoli that he should become "royal commissioner" for the city of Vicenza, a formerly (and, from the point of view of the citizenry, very unwilling) Austrian city which in July 1866 was evacuated by the Austrian garrison in the context of that year's so-called Third War of Independence. Mordini held the office of royal commisioner between, formally, 17 July and 22 October 1866, when the plebiscite that gave effect to the annexation of the Veneto to the Kingdom of Italy rendered the position of "royal commisioner" redundant.