The Province of Frosinone () is a province in the Lazio region of Italy, with 91 comuni (singular: comune; see Comuni of the Province of Frosinone). Its capital is the city of Frosinone. It has an area of and a total population of 493,605 (2016). The province was established by royal decree on 6 December 1926 with territories belonging to the then provinces of Rome and Caserta. The areas of the then province of Caserta were the left valley of the Liri-Garigliano river, the district of Sora, the Comino Valley, the district of Cassino, the Gulf of Formia and Gaeta, the Pontine islands, which until then had been for centuries included in the Province called Terra di Lavoro, of the Kingdom of Naples (or of the Two Sicilies). Most of these territories were part of the ancient Latium adiectum. Geography The province largely follows the territory of the low and middle Latin Valley, a larger region that extends from south of Rome to Cassino. In the eastern area, on the other hand, the Comino Valley extends along the border with Abruzzo. The territorial boundaries are mostly marked by mountain ranges: the Ernici Mountains to the north and the Lepini Mountains to the southwest, the Ausoni and Aurunci Mountains to the south, the Mainarde to the northeast. The mountain system of the territory of the province of Frosinone follows the natural development of the mountain ranges of the Italian peninsula; the two main systems are part of the central Apennines to the north, and the Lazio pre-Apennines to the south, divided by the low and middle Latin Valley crossed by the Sacco and Liri rivers. History The first traces of human presence in the provincial territory date back to prehistoric times: a famous skull of Homo erectus (Homo cepranensis, in the Prehistorical Museum of Pofi), dating from 800,000 years ago, constitutes the most ancient finding of the Homo species in Europe. In historical times (10th-9th centuries BC), the area, previously occupied by the so-called Pelasgic civilization, was settled by Indo-European colonists. This arrival is referred to in numerous legends, such as those of Aeneas and Saturn. The latter, ousted by Olympus, was said to come to Lazio to help the men and found seven cities whose name begins with "A" (for example, Alatri and Anagni). In the 7th century BC the area of what is now the province entered the orbit