Like Horace & Cicero the younger, Marcus Valerius Messala Corvinus was a student in Athens when Julius Caesar was assassinated (44 BCE). Despite his republican principles, he survived proscription to become a trusted colleague of Octavian. On the eve of the battle of Actium (31 BCE), Octavian chose Messala to replace Marc Antony as his co-consul.  After Antony's defeat he was given several commands in the East. He was the first governer of Syria appointed by Octavian (29 BCE).  After this he was sent to Gaul. He returned to Rome to celebrate a triumph for having crushed an uprising in Aquitania (27 BCE).  Having been named the first prefect of the city of Rome, he persuaded the Senate to designate Octavian as the "father of the fatherland" [pater patriae].  But as Octavian assumed absolute authority under the name of Caesar Augustus, Messala resigned his office in the new imperial order, having served only six days.

He remained an influential orator, author & patron of litterati of the Augustan age, such as Horace & Ovid.  Though none of his own works survive, his memoirs of the Roman civil wars became a prime source of information for later Roman historians, including Suetonius & Plutarch.

References: Appian, History of Rome: Illyrian Wars 4.17.
                   Tacitus, Annals 4.34, 6.11.
                   Suetonius, Twelve Caesars: Augustus 58, 74.
                   _____, Illustrius Men: Grammarians 4.
                   Cassius Dio, Roman History 49.16, 38; 50.10; 51.7.

Other resources on line:

• Marcus Valerius Messalla Corvinus - well-researched illustrated article in Wikipedia's web.