In time the vigour of the Merovingian kings declined, until the actual power was wielded by the steward of the royal household, the Mayor of the Palace. Gradually this office became hereditary in a dynasty of rulers known as Carolingian or Charles Dynasty. The first great Charles was Mayor Charles, surnamed Martel or the Hammer; the last, Charlemagne, or Charles the Great. The former derived his name from the crushing blows he inflicted upon his enemies, particularly the Saracens, the followers of Mohammed, who by this time (732) had replaced the Vandals along the north coast of Africa, conquered the Visigoths in Spain, and were threatening France. Charles met them at Poictiers or Tours, and in a complete victory saved Christianity to Europe. Charles remained simply Mayor; but the title of King was assumed by his son, Pepin, who was first elected by the Franks and then anointed by the Church, thus ascending the throne with the consent of the Pope. We have already noted how he repaid the debt. He was succeeded by his son Charlemagne, whose dream was to found an empire upon the ruins of the Roman. It was fulfilled to the point that he extended Frankish sway over Germany, as far as the Elbe, and into Italy. In the last named country he conquered the Lombards and signalised the completeness of the conquest by assuming the iron crown of Lombardy. On Christmas Day, <small>A.D.</small> 800, as he was kneeling at prayer in the Church of St. Peter in Rome, Pope Leo III crowned him Emperor of the Romans. It was the aim of Charlemagne to establish his government on Roman lines, to which end he reintroduced Roman laws and methods of civilisation and ordained that Latin should be the official language. The city selected as his capital was Aachen--Aix-la-Chapelle. [Illustration: S. APOLLINARE NUOVO, RAVENNA SHOWING CLASSICAL COLUMNS AND “IMPOST”: MOSAICS; ARCH OF TRIUMPH AND APSE. P. 201] [Illustration: S. APOLLINARE-IN-CLASSE, RAVENNA EXTERIOR OF APSE. DETACHED CAMPANILE. P. 201] [Illustration: CHURCH OF KALB-LAUZEH, SYRIA SHOWING APSE, WOODEN ROOF, SUPPORTED BY SMALL COLUMNS ON CORBELS; ROUND ARCHES ON PIERS. P. 200] [Illustration: CHURCH OF TURMANIN, SYRIA RUDIMENTS OF SUBSEQUENT ROMANESQUE AND GOTHIC TREATMENT OF WEST FRONT. P. 200] CHAPTER II EARLY CHRISTIAN AND BYZANTINE ARCHITECTURE