[451] In the early years of the thirteenth century, an Asiatic chieftain by the name of Genghis Khan built up a vast empire of Mongol or Tartar peoples, which for a time stretched all the way from China to eastern Germany. The rise and westward expansion of this barbarian power spread alarm throughout Christendom, and with good reason, for it was with great difficulty that the Tartar sovereigns were prevented from extending their dominion over Germany and perhaps over all western Europe. After the first feeling of terror had passed, however, it began to be considered that possibly the Asiatic conquerors might yet be made to serve the interests of Christendom. They were not Mohammedans, and Christian leaders saw an opportunity to turn them against the Saracen master of the coveted Holy Land. Louis IX.'s reception of an embassy from Ilchikadai, one of the Tartar khans, or sovereigns, was only one of several incidents which illustrate the efforts made in this direction. After this episode the Tartars advanced rapidly into Syria, taking the important cities of Damascus and Aleppo; but a great defeat, September 3, 1260, by the sultan Kutuz at Ain Talut stemmed the tide of invasion and compelled the Tartars to retire to their northern dominions. [452] May 21, 1249. [453] Joinville here gives an account of the first important undertaking of the crusaders--the capture of Damietta. After this achievement the king resolved to await the arrival of his brother, the count of Poitiers, with additional troops. The delay thus occasioned was nearly half a year in length, i.e., until October. [454] This was a common designation of Cairo, the Saracen capital of Egypt. [455] December 6. [456] The order of the Templars was founded in 1119 to afford protection to pilgrims in Palestine. The name was taken from the temple of Solomon, in Jerusalem, near which the organization's headquarters were at first established. The Templars, in their early history, were a military order and they had a prominent part in most of the crusading movements after their foundation. [457] At this point Joinville gives an extended description of the Nile and its numerous mouths. King Louis found himself on the bank of one of the streams composing the delta, with the sultan's army drawn up on the other side to prevent the Christians from crossing. Louis determined to construct an embankment across the stream, so that his troops might cross and engage in battle with the enemy. To protect the men engaged in building the embankment, two towers, called cat castles (because they were in front of two cats, or covered galleries) were erected. Under cover of these, the work of constructing a passageway went on, though the Saracens did not cease to shower missiles upon the laborers. [458] An instrument intended primarily for the hurling of stones.