Rieti is a town in Lazio, central Italy, with a population of c. 47,700. It is the capital of province of Rieti.

The town centre rests on a small hilltop, commanding a wide plain at the southern edge of an ancient lake. The area is now the fertile basin of the Velino River. Only the small Ripasottile and Cantalice lakes remain of the original large one.

Ancient era

Curius Dentatus drained a large portion of the lake by making the Velino a distributary of the Nera river. The wide area once occupied by the lake turned into a fertile plain. Following Roman customs, the land was split into characteristic square allotments. The town itself underwent significant development, being re-organized according to typical Roman urbanistic standards (e.g., two orthogonal roads make up the settlement's backbone), and was fortified with strong walls. A stone bridge was laid across the Velino river, and a large viaduct was built to bring goods from the Salaria road directly to Rieti's southern door.

Roman Reate deserved several quotations in Latin literature, thanks to its flourishing soil, its valued assets, and some peculiarities of the surroundings (such as wandering islands and hollow-subsurfaced fields). Cicero, for instance, describes the tensions between Reate and Interamna (Terni) following the lake drainage, and refers to the country houses (villae) that his friend Q. Axius owned in the plain.

Middle Ages

After the fall of the Western Roman Empire Rieti suffered destruction by Barbarians, but never ceased to be an important gastaldate during the Lombard domination, as part of the Duchy of Spoleto. Under the Franks, it was county capital. It was sacked by the Saracens in the 9th and 10th century and, by the Norman king Roger II of Sicily in 1149.

The city was rebuilt with the help of the Roman comune, and from 1198 was also a free comune, 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). Charles I of Anjou was crowned King of Apulia, Sicily and Jerusalem by Pope Nicholas I in 1289. Pope Gregory IX celebrated canonized St. Dominic in Rieti (1234).

Late Middle Ages and modern era

After the Papal seat had been moved to Avignon, Rieti was conquered by the King of Naples, while inner struggles between Guelphs and Ghibellines broke out. In 1354 it was won back by Cardinal Albornoz, and it later became a feudal seignory of the Alfani family within the Papal States. More of the surrounding plain was drained in the following century, but this led to confrontation with the neighboring Terni.

Rieti was province capital of the Papal States from 1816 to 1860. After the unification of Italy, it was initially part of Abruzzi, being annexed to Lazio in 1923. It became the provincial capital on January 2, 1923.