of the Pyrenees, a dependency of the Gothic kingdom. Gaul now lay open before them. The Mohammedan power threatened to encircle Christendom, and to destroy the Church and Christianity itself. In the plains between _Tours_ and _Poitiers_, the Saracens were met by the Austrasian Franks under _Charles Martel_ (732). The impetuous charges of the Saracen cavalry were met and beaten back by the infantry of the _Franks_, which confronted them like an iron wall. The Mohammedan defeat saved Christian Europe from being trampled under foot by the Mussulman; it saved the Christian people of the _Aryan_ nations from being subjugated by the _Semitic_ disciples of the Koran. At the same time that Spain was overrun, the Turkish lands on the east of the Caspian were subdued. The old antipathy between the Iranians and Turanians, the Schiite Persians and the Sunnite Turks, was afterwards carried into Europe by the Ottoman Moslems. THE ABBASSIDES: BAGDAD.--Misgovernment embittered the faithful against the rule of the _Omayyads_ in _Damascus_, although Syria had become a source of higher culture for the Arabians: there they became acquainted with Greek learning. The adherents of _Ali_ found vigorous champions in the _Abbassides_, who, as _Hashimites_, laid claim to the caliphate. One of them, _Abul Abbas_, was made caliph by the soldiers in 750. The fierce cruelty of his party against the _Omayyads_ led to the murder of all of them except _Abderrahman_, who fled to Africa, and, in 755, founded an independent caliphate at _Cordova_. The _Abbassides_ attached themselves to the _Sunnite_ creed. Under _Almansor_, the brother and successor of _Abbas, Bagdad_, a city founded by _Almansor_ (754-775) on the banks of the Tigris, was made the seat of the caliphate, and so continued until the great Mongolian invasion in 1258. Bagdad was built on the west bank of the Tigris, but, by means of bridges, stretched over to the other shore. It was protected by strong, double walls. It was not only the proud capital of the caliphate: it was, besides, the great market for the trade of the East, the meeting-place of many nations, where caravans from China and Thibet, from India, and from Ferghana in the modern Turkestan, met throngs of merchants from Armenia and Constantinople, from Egypt and Arabia. There trading-fleets gathered which carried the products of the North and West down the great rivers to the Persian Gulf and the Indian Ocean. _Bagdad_ was to the caliphs what _Byzantium_ was to Constantine, or _Alexandria_ to the Ptolemies. It became the grandest city in the world. Canals to the number of six hundred ran through it, and a hundred and five bridges bound its two parts together. It was furnished with many thousand mosques and as many baths. The palace of the caliphs comprised in itself all the splendor which Asiatic taste and extravagance could collect and combine in one edifice.