2nd husband of Julius Caesar's niece, Atia Balba
Stepfather of young Octavian (later Augustus)

2nd praetorian prefect of Syria under Pompey (61-60 BCE)
consul of Rome in 56 BCE.

A politically cautious descendent of Roman kings & wary of rivalries, Philippus did not take sides in the civil war between Pompey & Caesar and, due to his distrust of Marc Antony, tried unsuccessfully to dissuade his stepson from becoming Caesar's heir. Augustus rewarded him for his continued loyalty.

References: Suetonius, Life of Augustus 8.
                   Appian, Syrian Wars 8.51.

Other resources on line:

• Lucius Marcius Philippus -  entry in the Wikipedia web.