Gaivs Octavianus, better known as Augustus Caesar, (63 BC - 14 AD).
Augustus dramatically enlarged the Roman Empire, completed the conquest of the Iberian peninsula, North Africa, Egypt and the Middle East. Beyond the frontiers, Augustus secured the Empire with a buffer region of vassal states and made peace through diplomacy. He reformed the Roman system of taxation, developed networks of roads with an official Empire-wide courier system, established a standing well-trained Army and Fleet, established the Praetorian Guard, created official police and firefighting services for Rome, and rebuilt much of the city during his reign.
Not for nothing the era of Augustus is known as Pax Romana.