Perhaps the most significant was the cycle of stories of the exploits and adventures of Alexander the Great which originated in a Greek history purporting to be the work of Callisthenes, a companion of the Macedonian conqueror, and is hence known as the _Pseudo-Callisthenes_. Written in Alexandria about the beginning of the third century after Christ, this work subsequently became widely dispersed through the East, where translations were made into Syriac, Arabic, Ethiopic, and other Oriental tongues. Put into Latin by Julius Valerius about the middle of the fourth century, again translated in the tenth century,[204] given further Latin vernacular renderings with many additions at later dates, the Romance of Alexander had come, by the time of the Crusades, to form the nucleus of a mass of stories and fables whose scenes were laid in distant Asiatic countries. With it had been associated those mysterious tales and prophecies of Gog and Magog whose origins were ultimately connected with the Biblical revelations of the end of the world.[205] Alexander the Great and Gog and Magog appear in the _Pseudo-Methodius_, a book of prophecy which foretold the dread events of the Last Day. Rendered into Latin at an early period from a Greco-Syrian original, the _Pseudo-Methodius_ made a deep impression on the medieval mind, especially at the time of the Mongol invasions in the early thirteenth century. Writers of our period like Gervase of Tilbury and Giraldus Cambrensis also drew on the legends found in Geoffrey of Monmouth’s mythological history of Britain, many of which had entered into the composition of the Romance of King Arthur. Some of the latter were of slight geographical interest. Finally, the mythology and folklore of Ireland, with infusions from classical and even Arabic literature, gave rise to the story of the wanderings of St. Brandan[206] among mysterious islands in the Western Ocean, an account of which we have in a manuscript dating back perhaps to as early a period as the ninth century.[207] BOOKS OF TRAVEL AND DESCRIPTION The most important books describing actual travels and explorations written between the conversion of Constantine and the Crusades were for the most part in languages unknown to the men of the West—Greek and Arabic. Zemarchus’ account of the tribes and trade of Central Asia[208] and the _Meadows of Gold_ of Al-Masʿūdī, wherein were described things personally seen by the travelers between Spain and Burma and south as far as Madagascar, were treasures of geographical lore unknown to Occidental readers of this age. In Adam of Bremen’s _Gesta Hammenburgensis ecclesiae pontificum_, written in the latter half of the eleventh century, we find a description of the countries of the North. This was based on knowledge acquired from the voyagings of the Northmen between the eighth and eleventh centuries and, together with the Sagas, will be discussed in a later chapter.