Fitz

Fitz (pronounced "fits") is a prefix in patronymic surnames of Norman origin, that is to say originating in the 11th century. The word is a Norman French noun meaning "son of", from Latin filius (son), plus genitive case of the father's forename. Whilst Fitz is now the standard form used by modern historians the word appears in ancient documents with various spellings such as fiz, filz, etc. The word has developed in modern French to fils de, with which it is thus cognate.

Norman gentry and noble families under feudal society held one or more manors from an overlord, who himself held directly from the Duke of Normandy, the sovereign. Such families took their surnames from their principal manor on which they resided and which formed their seat. This was the case for example with William the Conqueror's great noble adviser Roger de Beaumont (c. 1015–1094), ("Roger from Beaumont"), who took his surname from his manor of Beaumont-le-Roger in Normandy. His eldest son was called Robert de Beaumont, again after the family seat.

However, where a distinguished Norman warrior perhaps held no land, and thus was not an established member of feudal society, or was from an obscure family, such a naming convention was unavailable. In such families therefore the word Fitz was preposed to the fore name of the warrior's father to give the warrior and his further descendants a surname by which they could be known. Thus Fitz Gilbert, meaning "son of Gilbert" would be adopted as a surname by the warrior christened "Baldwin", giving "Baldwin FitzGilbert". If we assume Baldwin's son was christened "William", his name would become "William FitzBaldwin FitzGilbert. However it is rare to find this naming practice extending beyond two generations and eventually the family name became "FitzGilbert" alone, the name of the patriarch, with the name of the patriarch's son being dropped. It must be asked why the father, in this case Gilbert, was not himself Fitz of his own father, the answer seems unclear. The Domesday Book of 1086, written in Latin, names a few examples such as Turstin filius Rolf, who was known in Norman-French documents as Turstin FitzRolf.

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