In 1452 Borso d'Este, then marquis of Modena and Reggio, was raised by Emperor Frederick III with the title of duke of Modena and Reggio. In 1471, Pope Paul II formally elevated him in as Duke of Ferrara, over which the family had in fact long presided.
This latter territory was lost to the Papal States in 1597, while the House of Este continued to rule the Duchy of Modena and Reggio in the Emilia region until 1796, when it became part of Napoleon Bonaparte's Cispadane Republic. In 1814, the duchy was restored under the Habsburg grandson of the last Este duke, continuing until it was annexed by Piedmont-Sardinia in 1859.