The prefix "Fitz" is of Norman origin. Following the invasion in 1066 the invaders brought their names with them and many of the Anglo-Saxon residents of England "Normanized" their names. The prefix comes from the Norman word "Fiz" (from the Latin "Filius") meaning "son of", which was then added to the father's name: FitzGerald, FitzPatrick, FitzRandolph, etc.Some royalty even went so far as to name their children with "Fitz" and then their title: FitzCount, FitzEmpress, FitzRoy (for the son of the king), etc. Fitz sometimes referred to the illegitmate son of an aristocrat, but not always. It is similar to the Welsh prefix "Ap", the Scottish "Mc", "Mac" or simply "M'" and the Irish "O". In Scandinavia the designation was placed at the end: "son" or "sen" for the son, and "dotter" for daughter, for example.