Person:Margaret Plantagenet (5)

The chronicler known as "Robert of Gloucester" wrote that the mother of Richard FitzRoy was "the erles daughter of Wareine". There's no corroboration of this statement. Nor is there any record of Prince John having a liaison with a Warenne girl (who would have been a half first cousin). So it could easily be a mistake.

If we take it at face value, John's mistress is unlikely to have been Earl Hamelin's eldest daughter, Maud, who had a busy marital career. It's perhaps not impossible that she was unknown younger daughter who died unmarried and unrecorded. Otherwise the choice falls between the Earl's two known younger daughters, Isabel and Ela. Earlier writers favored Ela, but modern scholarship tends to favour Isabel.

1.   daughter, in Cawley, Charles. Medieval Lands: A prosopography of medieval European noble and royal families.