With the annexation of the Kingdom of the Two Sicilies to the Kingdom of Italy, a type of guerrilla warfare was unleashed against the House of Savoy, better known as 'post-unification brigandage'.. The disregarded allocation of state-owned lands due to the heavy debt of the House of Savoy and the increase in taxes and cost of essential goods were the main causes of the revolt, which many historians believe to be one of the first civil wars in contemporary Italy.