Baghdad is not an old city. Although there was probably a village on the site time out of mind, it does not come into any prominence until the eighth century of our era. As the residence of the Abasside caliphs it rapidly assumed an important position. The culmination of its magnificence was reached in the end of the eighth century, under the rule of the world-famous Haroun-el-Raschid. It long continued to be a centre of commerce and industry, though suffering fearfully from the various sieges and conquests which it underwent. In 1258 the Mongols, under a grandson of the great Genghis Khan, captured the city and held it for a hundred years, until ousted by the Tartars under Tamberlane. It was plundered in turn by one Mongol horde after another until the Turks, under Murad the Fourth, eventually secured it. Naturally, after being the scene of so much looting and such massacres, there is little left of the original city of the caliphs. Then, too, in Mesopotamia there is practically no stone, and everything was built of brick, which readily lapses back to its original state. For this reason the invaders easily razed a conquered town, and Mesopotamia, so often called the "cradle of the world," retains but little trace of the races and civilizations that have succeeded each other in ruling the land. When the Tigris was low at the end of the summer season, we used to dig out from its bank great bricks eighteen inches square, on which was still distinctly traced the seal of Nebuchadnezzar. These, possibly the remnants of a quay, were all that remained of the times before the advent of the caliphs. II THE TIGRIS FRONT