Esperia was founded in 1867 by the merger of the municipalities of Roccaguglielma and San Pietro in Curolis. The name Esperia recalls the ancient name of the Italian peninsula. Roccaguglielma had been founded in the Middle Ages by the Norman, William of Glossavilla, and appears for the first time in a 998 document as a possession of the Abbey of Montecassino. To this location the population fled after the invasions of the Saracens.
Due to its strategic location in a mountain pass, which connected directly with Aquino Gaeta without going through Cassino, it often suffered sieges and destruction. From the fourteenth century there were changes to the feudatory families: the Spinelli, the Della Rovere and the Farnese. It experienced a period of remarkable welfare until in 1636 it became part of the royal property when its economic conditions deteriorated due to frequent earthquakes and heavy taxes.
During the nineteenth century this was the area of the bandit raids of Fra Diavolo, a native of nearby Itri. It suffered heavy bombing during the Second World War being on the Gustav Line.