Province of Venice
After the Congress of Vienna in 1815 all the lands to the north of the Po were included into the Kingdom of Lombardy-Venetia; part of these lands, the western and central lands, were annexed to the Territory of Rovigo to establish the Province of Rovigo in the Kingdom of Lombardy-Venetia. The eastern lands were at first annexed to the Province of Venice; on 1851 the whole Po delta was detached from the Province of Venice and attached to the Province of Rovigo, thus giving the Polesine the extension it has nowadays.