Italia was the name of the Italian peninsula during the Roman Empire.
During the Republic and the first centuries of the empire, Italia (which extended at the beginning from Calabria to Rubicon, starting from Augustus from Calabria to the Alps) was not a province, but rather the territory of the city of Rome, thus having a special status: for example, military commanders were not allowed to bring their armies within Italia, and Julius Caesar passing the Rubicon with his legions marked the start of the civil war.
The name Italia covered an area of land whose borders evolved over time. According to Strabo (Geographia, v 1), at the beginning the name indicated the land between the strait of Messina and the line connecting the gulf of Salerno and gulf of Taranto; later Italia was extended to include the whole Italian peninsula, as well as the Istrian town of Colonia Pietas Iulia (Pola); finally, Julius Caesar gave Roman citizenship to the people of the Gallia Transpadana— that part of…