When the French invaded, Pezza was recalled to active duty, and ordered to organize a guerrilla column to resist the attackers. But the French moved so fast he was barely able to escape, and fled with his brothers to Sicily. He soon returned, however, and, on 23 March 1806, clashed with the French near Itri. Shortly afterwards, Pezza was recalled to Sicily to gather more forces, and in April joined an expedition to reinforce Gaeta that was led by the British admiral Sir Sidney Smith, one of Napoleon's most inveterate foes.