In April 1398, and again in March 1399, Boniface IX ordered to be preached throughout Christendom a crusade for the defence of Constantinople.[589] His appeals fell on deaf ears. Wenceslaus was approaching the end of his power in the empire, Richard of England was fighting for his throne, Florence was in a struggle with the Visconti, the Duke of Burgundy and the Duke of Orleans were disputing the regency in France. Only Venice and Genoa were vitally interested in the fate of Constantinople. Because Genoa had put itself under the guardianship of the Duke of Orleans, brother of Charles VI of France, and son-in-law of Duke Giovanni Visconti of Milan, the interests of her Pera colony demanded some attention from the powerful Valois and Visconti families. This made possible the sole response to the appeals of Manuel and the Pope, the expedition of Marshal Boucicaut. In the summer of 1399, a force of ten thousand Osmanlis, after coming into more or less open conflict with the Genoese of Galata, attempted to enter Constantinople. The defenders were few; for the inhabitants, as at the time of the final siege in 1453, were more likely to be found in the bazaars than on the city walls. They had little desire to prolong a condition which was paralysing their business activities. Clavijo, who visited Constantinople four years later, was informed that the attack failed only because of the lack of skill and energy shown by the Osmanlis.[590] Until they had cannon to help them, the Osmanlis never displayed fighting ability in an assault upon fortifications. At this critical moment, aid arrived from Europe. Boucicaut was the only one of the prisoners of Nicopolis that accepted the challenge of Bayezid. He did not forget the biting words of the audience at Brusa at the time of their release. On June 26, 1399, with four ships and two armed galleys, he set sail from Aiguesmortes. His force of twelve hundred chevaliers and foot-soldiers had much more cohesion and experience than the volunteers who gathered round Jean de Nevers at Dijon three years before. He was joined at Tenedos by several Genoese and Venetian galleys. After a victory in the Dardanelles over seventeen Ottoman galleys, the first recorded naval combat of the Osmanlis, Boucicaut reached Constantinople ‘just in time to save the city’. He was received with great joy by Manuel, and given the rank of Grand Constable.[591]