Frascarolo belonged to the Country (Contado) of Lomello in medieval times, until it came under the rule of Pavia, as certified by Frederick I in 1164. It appeared in 1250 under the name of Frascarolum on the list of lands under the dominion of Pavia. In 1441, Antonio Birago of Milan became the ruler of Frascarolo, including the nearby Torre Beretti. The estate was sold in the late 14th century to the Varesini family and later on to the Bellisomi of Pavia who were invested with the title of Marquises of Frascarolo by the King of Spain, Philippe IV, in 1623. The Bellisomi kept the property until 1797, when feudalism was abolished.