In the former half of the sixth century, Justinian was Emperor of the East. His empire nearly corresponded in geographical extent with the country which we now call Turkey in Europe. During his reign, Constantinople was visited by a company of warlike strangers, whose savage aspect filled all the people with amazement and fear. Their long hair, which hung in tresses down their backs, was gracefully bound with ribbons, but in the rest of their habit they resembled the Huns. These were the first Turks ever seen in Europe. They had come to offer the Emperor their alliance, which was accepted at a given price. They had travelled from the foot of Mount Caucasus, where they first heard of the splendor and weakness of the Roman Empire. Their origin was beyond that celebrated ridge, and in the midst of another no less celebrated, and which is variously known as the Caf, the Imaus, the Golden Mountains, and the Girdle of the Earth. Here lived the people called Geougen, governed by a great Khan. In the hills they inhabited were many minerals. Iron and other mines were worked for them by the most despised portion of their slaves, who were known by the name of Turks. These slaves, under Bertezena, one of their number, rebelled against the great Khan, and succeeded in possessing themselves of their native country. From freedom they proceeded to conquest, and it was in the course of their victories that they found their way to the Caucasus. Nearly a century elapsed, and Heraclius was Emperor. He formed an alliance with the Turks, and so honored their prince as to place the imperial diadem on his head, and salute him with a tender embrace as his son. In the ninth century the Turks were introduced into Arabia. The Caliph Motassem employed them as his own guards in his own capital. He educated them in the exercise of arms, and in the profession of the Mahometan faith. No less a number than 50,000 of these hardy foreigners did he thus foolishly establish in the very heart of his dominions. In due time they became masters of some portions of the country into which they had been admitted as mercenaries. For one of their princes, Mahmood or Mahmud, the title of Sultan was invented, about a thousand years after Christ. Its meaning is autocrat or lord. His conquests were very extensive, and stretched from Transoxiana to Ispahan--from the shores of the Caspian to the mouth of the Indus.