Cusack is an Irish family name of Norman origin, originally from Cussac in Guienne (Aquitaine), France.[1] The surname died out in England, but is common in Ireland, where it was imported at the time of the Norman invasion of Ireland in the 12th century. While not particularly common, the name Cusack is historically associated with a number of variant forms, such as de Cussac, de Ciusak, de Cíosóg, de Ci'omhso'g, MacIosog, and Mac Isog. Irish emigrants to America were given alternative spellings by immigration officers, based on their pronunciation . Hence, Kuzak, Kuzack, Cusick, and Cussack are modern variants. In 1211, Geoffrey and André de Cusack came to Ireland with King John[2]. The family served as lairds of Killeen (see Killeen Castle, Dunsany), Co. Meath, and Tirawley in Mayo.