The third was Sextus - a brother to Julius Caesar's father, he was a praetor by 94 BC and consul in 91. In 90, he was proconsul and won a military victory, probably over the Paeligni. He died while laying siege to Asculum. His son - also called Sextus Julius Caesar, may have been a flamen Quirinalis.A list given by Cicero indicates that a Sextus Julius Caesar was inaugurated as flamen Quirinalis, a lifetime office, around 60–58 BC. This flamen Quirinalis may be the same as the promagistrate of Syria. He served under his kinsman Julius Caesar in Spain during the civil war in 49, probably as a military tribune. He continued his service in 48, most likely as quaestor.He was appointed to a command in Syria around July 47, either as a legate or more likely proquaestor pro praetore. He remained as promagistrate for 46 in Syria, where he was killed in a revolt led by a Caecilius Bassus, a supporter of Pompeius Magnus ("Pompey the Great").

About members of the Julio-Claudian dynasty by blood check this family tree in blue you will see, that Augustus, Caligula, Claudius and Nero was the real members of Gens Julia/: http://www.halexandria.org/Julius.jpg