For the most part, crime was viewed as a private matter in Ancient Greece and Rome. Even with offenses as serious as murder, justice was the prerogative of the victim's family and private war or vendetta the means of protection against criminality. Publicly owned slaves were used by magistrates as police in Ancient Greece. In Athens, a group of 300 Scythian slaves was used to guard public meetings to keep order and for crowd control, and also assisted with dealing with criminals, manhandling prisoners, and making arrests. Other duties associated with modern policing, such as investigating crimes, were left to the citizens themselves. The Roman Empire had a reasonably effective law enforcement system until the decline of the empire, though there was never an actual police force in the city of Rome. When under the reign of Augustus the capital had grown to almost one million inhabitants, he created 14 wards, which were protected by seven squads of 1,000 men. If necessary, they might have called on the Praetorian Guard for assistance. Beginning in the 5th century, policing became a function of clan chiefs and heads of state.