The despatch of the Egyptian fleet, which was defeated by Almeida, was a proof that King Emmanuel's fears were justified. The internal wars of the principal Muhammadan rulers alone prevented that fleet from being followed at once by others still more formidable. Fortunately for the Portuguese, however, at this very period the Sultan Selim I of Constantinople was engaged in fierce war with the Mameluke Sultan of Egypt, and Ismáil Sháh of Persia was at open issue with both dynasties. But the necessity for closing the former trade routes would {151} not have led to the ruin and slaughter of Muhammadans settled in India itself, had they not systematically opposed the Portuguese. Albuquerque, after his first conquest of Goa and after that of Malacca, showed himself ready to treat the Moslems with clemency. In both instances that clemency was abused. The Muhammadans of Goa undoubtedly favoured the advancing army of Yusaf Adil Sháh; and the Muhammadans of Malacca began to plot against the Portuguese supremacy as soon as it was firmly established. It was for these reasons that he ordered the indiscriminate slaughter of the Muhammadans of Goa on his second conquest of that city, and that he directed the execution of Utemuta Rájá at Malacca. It was impossible that the two rival trading nationalities could co-exist; the one was inevitably led to destroy the other. The first means devised for the overthrow of Muhammadan commerce was the system of licenses. Before Albuquerque's arrival the Portuguese arrogated to themselves the right of seizing any ship which did not carry a license granted by the Portuguese authorities. When this custom had been thoroughly established, it was followed by the complete prohibition of all licenses to trade with the Red Sea. Even when such a powerful ruler as the king of Gujarát asked permission to send ships to Aden, Albuquerque refused, and every vessel carrying merchandise in that direction was regarded as legitimate prey. The next step to closing the sea by means of {152} the superiority of the Portuguese vessels was to build fortresses in spots commanding the trade routes. This was why Albuquerque laid such weight on the necessity of building a fortress at Ormuz, and of endeavouring to capture Aden.