Alfonso II
When Alfonso's grandson Alfonso II d'Este—Robert Browning's duke of "My Last Duchess"—produced no male heir, the main d'Este line died out. A grandson of Alfonso I and cousin of Alfonso II, Cesare d'Este had been born out of wedlock. He was recognized by the Emperor but not by the Pope, who took the Duchy of Ferrara by force. Nevertheless, the House of Este continued in Modena and Reggio.