Slovakia in the Roman era
The reign of Augustus (27 BC - 14 AD) began a long period known as the Pax Romana, or Roman peace. Despite continuous wars on the frontiers, and one year-long civil war over the imperial succession, the Mediterranean world remained at peace for more than two centuries. Augustus enlarged the empire dramatically, annexing Egypt, Dalmatia, Pannonia, and Raetia, expanded possessions in Africa, and completed the conquest of Hispania.
By the end of his reign, the armies of Augustus had conquered the Alpine regions of Raetia and Noricum (modern Switzerland, Bavaria, Austria, Slovenia), Illyricum and Pannonia (modern Albania, Croatia, Hungary, Serbia, etc.).
Legionary
As Augustus consolidated power in 27BC and founded the Principate, he further professionalized the Roman legionary. Under him, a legionary's term of service was raised to 25 years (before that, a legionary's average term of service was only 10 years) and pay was standardized throughout the legions. Other than the gradual provincialization of recruits and the evolution of some military equipment, Roman legionaries would remain broadly unchanged until the end of the Pax Romana. These legionaries would expand Rome's borders to include lower Britannia, Dacia, North Africa, and more through military campaigns under Augustus and future emperors.