Tolfa was inhabited by the Etruscans, from whom there remains a necropolis, and then the Romans. It owes its fortune to the first discovery around 1460 of deposits of alunite (Aluminilite), used in paper manufacturing and skin care. Alum is derived from Alunite,
Rapid development occurred with the arrival of Agostino Chigi, a noble from Siena, so much so that the Pope decided that the money earned could finance the war against the Turks (as documented in “Appaltum Alluminum Sanctae Crociatae”).
Before the fall of Constantinople alum was sourced from Turkey, but then the demand led to a sudden development of Tolfa, which became autonomous and expanded rapidly beyond its walls, giving rise to the town of Allumiere.