His elder brother was Gnaeus Pompeius .
Sextus Pompeius was the youngest son of Gnaeus Pompeius Magnus ( Pompey the Great ) by his third wife , Mucia Tertia .
Sextus Pompeius ' elder brother son   Pompeius .
Sextus Pompeius was the youngest son of Gnaeus Pompeius Magnus ( Pompey the Great ) by his third wife , Mucia Tertia .