Bourbon troops were ordered to retreat eastwards and evacuate the island. An insurrection that had broken out in Catania on 31 May, led by Nicola Fabrizi, was crushed by the local garrison, but the order to leave for Messina meant that this Neapolitan tactical success would have no practical results. At the time only Syracuse, Augusta, Milazzo and Messina remained in royal hands in Sicily. In the meantime Garibaldi issued his first law. A levy failed to muster more than 20,000 troops, while the peasants, who hoped for an immediate relief from the grievous conditions to which they were forced by the landowners, revolted in several localities. At Bronte, on 4 August 1860, Garibaldi's friend Nino Bixio bloodily repressed one of these revolts with two battalions of Redshirts. The pace of Garibaldi's victories had worried Cavour, who in early July sent him a proposal of immediate annexation of Sicily to Piedmont. Garibaldi, however, refused vehemently to allow such a move until the end of the war. Cavour's envoy, La Farina, was arrested and expelled from the island. He was replaced by the more malleable Agostino Depretis, who gained Garibaldi's trust and was appointed as pro-dictator. On 25 June 1860, King Francis II of the Two Sicilies had issued a constitution. However, this late attempt to conciliate his moderate subjects failed to rouse them to defend the regime, while liberals and revolutionaries were eager to welcome Garibaldi. On 20 July Garibaldi attacked Milazzo with 4,000 men, under the command of Medici and Cosenz, against Bosco's 4,500. On 1 August, Bosco surrendered with honors, and was taken by ship to Real Cittadella, which was soon under siege. Over the next three weeks, with firm control of Sicily, Garibaldi prepared to cross the Straits of Messina. Landing and conquest in Calabria On 19 August Garibaldi's men disembarked in Calabria, a move opposed by Cavour, who had written the Dictator a letter urging him to not cross the strait. Garibaldi, however, disobeyed, an act which had the silent approval of King Victor Emmanuel. According to Schneid, "The timing of Garibaldi's crossing of the Straits of Messina and the invasion of the Papal States was more than coincidence. The Bourbons had some 20,000 men in Calabria, but, apart from some episodes like that of Reggio Calabria, which was conquered at high cost by Bixio on 21 August, they offered insignificant resistance, as numerous units of