Here was also kept a remarkable breed of dogs, who were trained not only as watch dogs but to render services similar to those afforded by the Alpine dogs of St. Bernard. As time went on the Sultans became more and more jealous of the naval power possessed by the Order. With the fall of the Eastern Empire and the final retaking of Constantinople by Mahomet II, in 1453 (See "Prince of India"), it was made evident that danger to the Order from this direction was rapidly increasing. This became so urgent that in 1470, after Mahomet had taken the island of Negropont, the Grand Master commanded that all members of the Order should repair at once to Rhodes. In 1476 d'Aubusson began the most active measures for the defense of the place, and thus was ready for the attack, in May, 1480, when 80,000 men in 160 ships, landed on the island coast. In this siege no small part was played by renegade traitors, the most prominent being one George Frapant, a German, whom the Grand Master finally hung in July. In the last sorties which terminated this siege deeds of the greatest bravery were performed; yet here we can only commemorate the fact that the Turks were summarily defeated, leaving 3,500 corpses on the ground after the last decisive attack. The losses of the besieged were small as compared with those suffered by the Turks. Later in the same year the island suffered from a severe earthquake. Mahomet died not long after this, was succeeded by his son Bo-jazet who made truce with the Order, presenting them with a relic of supposedly inestimable value, namely the hand of St. John, which the Turks had taken at Constantinople. Years of comparative quietude succeeded until in the following century, in 1522, Solyman the Magnificent landed upon the island in July, with 100,000 soldiers and 60,000 pioneers. Again ensued all the horrors of a siege. The defenders did their part so bravely that the Sultan publicly disgraced his generals. But the inevitable famine wrought consequent disaffection on the part of the native population, who clamored for capitulation, and sought treasonable terms therefor, because of which one of the most prominent of them was tried, found guilty and executed. Finally under stress of circumstances no longer endurable Grand Master Adam agreed to honorable surrender, and on the first of January, 1523, the Hospitaller Knights relinquished the island, the Sultan himself speaking in terms of extravagant praise of their heroism, while at the same time he scathingly censured the Christian monarchs of Europe who had failed to come to their relief. Thus after two hundred and twenty years of occupation and rule of the island of Rhodes, some 5,000 Knights and other members of the Order, and natives, left it to take abode for a short time in their Priory at Messina. Driven from here by plague, they moved on to Viterbo, while their Grand Master travelled in search of a new home.