Reate was originally a major site of the Sabine nation. After the Roman conquest, carried out by Manius Curius Dentatus in late 3rd century BC, the village became a strategic point in the early italic road network, dominating the "salt" track (Via Salaria) that joined Rome to the Adriatic Sea across the Appennine mountains. Through a deep cut in the limestone at the northern edge of the valley, Curius Dentatus made the water of the lake flow away in the Nera river, then the wide area once occupied by the lake turned into a fertile plain, and the land was split by surveyors into square allotments, in the shape of a regular grid. The town itself was re-founded on the basis of orthogonal axes, and was fortified with strong walls all around; a stone bridge was laid across the Velino river, and a great viaduct was built to lead people and carts from the Salaria road up to the southern door of the town. Roman Reate deserved several quotations in the Latin literature thanks to its flourishing soil, its valued asses, and some weird peculiarity of the surroundings, as wandering islands, roaming sources and hollow-subsurfaced fields. Cicero tells about litigation between Reate and Interamna for the lake drainage, and refers to the country houses (villae) that his friend Q. Axius owned in the plain. After the fall of the Western Roman Empire, Rieti suffered destruction by barbarians people, but was always an important gastaldate during the Lombard domination, as part of the Duchy of Spoleto. Under the Franks, it was capital of county. In the 9th and 10th centuries, it was sacked by the Saracens, and, in 1149, by the Norman king Roger II of Sicily. The city was rebuilt with the help of the Roman commune, and from 1198 was also a free commune, of Guelph orientation, with a podestà of its own. As a favourite Papal seat, Rieti was the place of important historical events: Constance of Hauteville married here by proxy Emperor Henry VI (1185); in the cathedral, in 1289, Charles I of Anjou was coronated King of Apulia, Sicily and Jerusalem by Pope Nicholas I. Pope Gregory IX celebrated here the canonization of St. Dominic (1234). After the Papal seat had been moved to Avignon, Rieti was conquered by the King of Naples, while inner struggles between Guelphs and Ghibellines began. In 1354 it was captured back by Cardinal Albornoz, and later was a feudal seignory of the Alfani family within the Papal States. In the following century a program of drying of the neighbouring plain was carried on, but this led to quarrels with the city of Terni. Rieti was province capital of the Papal States from 1816 to 1860. After the unification of Italy, it was initially part of Umbria, being annexed to the Lazio in 1923. It became capital of province on January 2, 1923.