The Turkish power depended upon the characteristic institution of the Janissaries. From the time of Orchan it was the law of the Turks to require from all the Christian subjects of their power a tribute of their children. These were at once made Mussulmans, brought up very strictly in their faith, skilfully taught, and trained to hardness. As time showed their capacity, they were divided into two classes; those who had no special physical strength were set to work in the offices of State; the others underwent the strict discipline which produced the finest military corps in Europe, the Janissaries. Unmarried, without family ties, connected neither among themselves nor with the people, these soldiers, it was said by their founder, Khalil-Djendereli, would belong solely to their sovereign, from whom they would have their sole reward. It was an original and daring thought, to make each conquest the basis of future victories. "Let the Christians support the war; let themselves furnish the soldiers by whose means we shall fight." The first batch of Christian captives thus set apart in 1328 were brought before a renowned dervish, Hadji Bektash. Thus he blessed them. "Let them be called Yeni-Tscheri (new soldiers): they shall be conquerors in every fight; let their countenance be ever white and shining, their arm strong, their sword sharp, their arrow swift." No troops ever more powerfully affected the imagination of friends and foes. Among the Turks they were always the leaders, the forlorn hope. Among Christians the terror of their name spread over Europe. In every war they gained new laurels, and from the moment when they stormed the walls of Constantinople they began to be, slowly but certainly, the sole strength of the Ottoman power. At first the absolute servants of the Sultan, before two centuries were over they became his masters. Their numbers increased rapidly. Within a few years their numbers reached twelve thousand, and in the seventeenth century they were more than three times as numerous. The description of the English traveller Sandys shows perhaps better than any other record what impression they made upon Christians at the height of their power.