Pomezia was founded as part of the draining and reclamation of the Pontine marshes, a huge 10-year operation initiated and undertaken by Benito Mussolini. A large infrastructural system of canals, dikes and pumping stations was put in place to turn the marshes into productive polders. Another aim was to beat the malaria and improve the hygienic circumstances. An army of 124.000 people was working on the project at the pinnacle around 1933.
Next to the reclamation a number of New Towns were built, amongst them Littoria, Sabaudia, Pontinia and Aprilia and a number of smaller villages.
The first inhabitants were poor migrants, mostly fascist families being resettled from the northern provinces of Veneto and Friuli, working the agricultural land. Many documentaries have been made on this topic and the harsh conditions of the first (and present day) workers and migrants.
During the war, Pomezia was seriously damaged.