 In 1815 the merger of the Kingdom of Naples, which included San Massimo, and that of Sicily led to the formation of the short lived Kingdom of Two Sicilies.In 1860, the Sardinian forces of Giuseppe Garibaldi conquered the region, leading to the formation of the Kingdom of Italy.Many residents of San Massimo fought and died for Italy in the First World War, as commemorated in the city center by the "Monument to the Fallen of the Great War," opened in 1920.