Gilbert FitzRoy was an illegitimate son of Henry I of England.
His maternity is unknown as well as almost everything about him, except that he was still young and unmarried in the 1140s.
[1] He died before 1143, at the age of ~12.
His mother was likely either Isabella de Beaumont, Nest ferch Rhys, or Sybil Corbet.
This English biographical article is a stub.