 In 1798, after the Napoleonic invasion of Piedmont, it was annexed to the Ligurian Republic; the French, who had conquered Serravalle after the battle of Marengo, had its castle destroyed.In 1815 the Congress of Vienna restored the town to the House of Savoy.In 1935 the Autostrada A7 (Genoa-Serravalle) was inaugurated, this became the fastest connection from Turin and Milan to the sea.