The Catalans were fast becoming an important naval power in the Mediterranean, and their King fostered its growth with care. He established arsenals and dockyards at Barcelona, Tortosa, Cullera, and Valencia, and ordered smaller yards to be formed at every port where there was anchorage for his galleys. Cullera and Tortosa were his principal dockyards. The men were so well trained, the galleys and arms were kept in such a state of efficiency, that Pedro was well able to take up Conradin’s glove and to avenge the death of Manfred, the father of his beloved wife Constance. The call soon came. The King of Aragon was moved to anger when he heard of the death of his father-in-law and of young Conradin. Before taking any steps against the usurper, he thought it well to secure himself from attacks on the side of France. His brother of Majorca was also anxious for his Continental dominions. St. Louis of France had been succeeded in 1270 by his son Philip _le Hardi_, who had married Pedro’s sister. An interview was arranged between the Kings of France, Aragon, and Majorca at Toulouse. The negotiation which followed was so far satisfactory that Philip solemnly swore never to interfere in the affairs of Montpellier, and professed warm friendship for both the Aragonese Kings. At this juncture the tyranny of the French led to the ‘Sicilian Vespers.’ The people rose throughout Sicily while Charles of Anjou prepared to wreak vengeance upon them, collecting a large army and fleet. The Sicilians turned to the King of Aragon, whose wife was the heir to their King, for help in their sore need, and their appeal was not in vain. He was engaged in some successful operations on the coast of Barbary, with a large, well-appointed fleet, when the message reached him. Pedro did not hesitate. He would take up Conradin’s glove and defend the right. With a fair wind, he caused his fleet to shape a course for Sicily. The King of Aragon landed at Trapani on August 28, 1282. The whole population of Sicily was overjoyed. The march from Trapani to Palermo was a triumphal procession. Pedro was crowned King of Sicily at Palermo, and immediately afterwards he marched to Messina, to resist any attempt to invade the island on the part of the French forces of Charles of Anjou. Charles arrived before Messina with his army, where he received envoys from the King of Aragon. They told him, in the name of their master, that he was a usurper; that he knew well that he had no right to the kingdom, which belonged to the Queen of Aragon and her sons as heirs of King Manfred, and demanded that he should leave it. Charles replied defiantly, and Pedro, calling all the able-bodied men of Sicily to arms, prepared to advance to Messina and attack the usurper, who was besieging the town, by sea and land.