Lucius was the son of Sextus II Julius Cæsar but his mother is unknown. The date and place of his birth have not been found.
His wife was Popillia Laenates. They were married, but the date and place have not been found. Their two known children were Lucius III Julius Cæsar (c0135BC-0087BC) and Gaius Julius Cæsar Strabo Vopiscus (c0130BC-0087BC).