When a "family detective" starts researching “Royalty” connected to one’s family, there arises women known as “Mistresses” and “Concubines”. Most Kings had them. Do you know the difference in these terms or “titles”?
A concubine can be part of a harem, or a “purchased” woman (slave), usually of inferior rank who cohabits for sexual relief, a “secondary wife”.
A mistress is a lady who has a continuing sexual relationship with a married man who is not her husband and generally receives material support. Title of mistress can also be a lady who has a position of authority, control or ownership such as “Mistress of the household”, or “Mistress of a Culinary Art”, Head Mistress of a College, etc.
Children of these ladies were, most of the time, recognized and given titles, land, or positions befitting (at the time) part royal blood.
The Irish surname FitzGerald is thought to derive from Gerald de Windsor, a Cambro-Norman nobleman whose son and grandson were involved in the Norman invasion of Ireland. Surnamed FitzRoy, FItzJames, FitzClarence (son of the King), some had the "Fitz Count" (son of the mother, if she was more noteworthy); and yet, "FItz" does not always mean illegitimacy - a somewhat complicated prefix handed down from the Normans and changing throughout the centuries.
The Irish name Fitzpatrick does not indicate a Norman origin of the family; it is the translation into English of the Gaelic surname Mac Giolla Phádraig. Other surnames beginning "Mac Giolla" were made into "McGilli-" (e.g. McGillicuddy), but the Fitzpatricks claimed Norman heritage in a time when the Normans dominated much of Ireland.
PHOTO: Desmond FITZGerald (1888 – 1947), an Irish revolutionary, poet and Cumann na nGaedhael politician
some Wikipedia sources.