Provinces were generally governed by politicians of senatorial rank, usually former consuls or former praetors. A later exception was the province of Egypt, incorporated by Augustus after the death of Cleopatra; it was ruled by a governor of only equestrian rank, perhaps as a discouragement to senatorial ambition. This exception was unique, but not contrary to Roman law, as Egypt was considered Augustus' personal property, following the tradition of the kings of the earlier Hellenistic period.
The Latin term provincia also had a more general meaning of "jurisdiction".
The Latin word provincia originally meant any task or set of responsibilities assigned by the Roman senate to an individual who held imperium ("right of command"), which was often a military command within a specified theater of operations. Under the Roman Republic, the magistrates were elected to office for a period of one year, and those serving outside the city of Rome, such as consuls acting as generals on a military campaign, were assigned a particular provincia, the scope of authority within which they exercised their command.
The territory of a people who were defeated in war might be brought under various forms of treaty, in some cases entailing complete subjection (deditio). The formal annexation of a territory created a province, in the modern sense of an administrative unit that is geographically defined. Republican-period provinces were administered in one-year terms by the consuls and praetors who had held office the previous year and who were invested with imperium.
Rome started expanding beyond Italy during the First Punic War. The first permanent provinces to be annexed were Sicily (Sicilia) in 241 BC and Sardinia (Corsica et Sardinia) in 237 BC. Militarized expansionism kept increasing the number of these administrative provinces, until there were no longer enough qualified individuals to fill the posts.