Summary - The topic of constitutional history in Giacomo Perticone must be situated in the debate that took place in Italian public law doctrine in the Twenties and Thirties. The Author, after outlining the discussion on the method and institutions of mass society in the Fascist period, draws a parallel between the work of Perticone and Maranini, the two scholars who, more than any others, carried forward the historico-constitutional approach until the Sixties. In the concluding part of the essay, the Author suggests that constitutional history should focus its main attention on the «political regime» and on the politically significant subjects that act within it.