Luigi Villari, 1911 Encyclopædia Britannica, Volume 9… (1911)
“ The Italian titles and estates were inherited by Folco I. (1060–1135) , son of Alberto Azzo by his second wife Gersende, daughter of Herbert I., count of Maine. [2] The house of Este played a great part in the history of medieval and Renaissance Italy, and it first comes to the front in the wars between the Guelphs and Ghibellines; as leaders of the former party its princes received at different times Ferrara, Modena, Reggio and other fiefs and territories. ”
