Cusack is an Irish family name of Norman origin Cussacq, which is originally from Cussac in Guienne, France. The surname has diminished in common use in England, but is still common in Ireland, where
Killeen Castle, located in Dunsany, County Meath, Ireland, is the current construction on a site occupied by a castle since around 1180. The current building is a restoration of a largely 19th-century
Cusack
…into the "land of war". Geoffrey de Cusack Lord of Killeen, having occupied his lands in 1172, built his castle. Over the doorway of Killeen Castle (see Killeen Castle Co.Meath) the date of the building is given as 1181. An early description of Killeen Castle reads…