Agrippa and his doppelganger.

Marcus Vipsanius Agrippa, more informally known by only his cognomen, was a Roman politician of the first century BC. Born in 63 BC, he came from an equestrian background, but by 44 BC he was Augustus' (then Octavian's) closest friend and most trusted military adviser. He defeated Sextus Pompeius at Naulochus in 36 BC, and, more importantly, he defeated the fleet of Marc Antony and Cleopatra VII Philopater at Actium in 31 BC. The way he managed such a feat was by using ships called "Liburnian galleys," which were tiny in comparison to the gargantuan quinqueremes that Antony preferred, a feature that made them easier to maneuver and faster than the giant warships.
Agrippa was consul of Rome by 33 BC, but at that point he accepted an aedileship, which made him the first water commissioner of Rome. This meant that he erected public bathhouses, revamped the cloaca maxima, and built a stagnum. He also built a series of roads across Gaul that connected sort of like modern-day interstates. Agrippa was granted permission by Augustus to marry Augustus' only daughter, Julia the Elder. She bore him five children. The girls were Julia the Younger and Agrippina the Elder, and the boys were Agripps Postumus, Gaius, and Lucius. Gaius and Lucius became the official heirs of their grandfather. Agrippa died on March 20, 12 BC, with highest honors as one of Rome's finest generals and most influential consuls to help the Republic transition into the Principate.