From the book ‘Practical Knowledge For All: A Comprehensive Self-Educator in Five Volumes, Volume 1, (I estimate it was published between 1956 and 1959), The Waverley Book Company, London, edited by Gordon Stowell.
The Clash of Cross and Crescent
Early in the 8th century the Mahomedan attack on Christendom was renewed. Walid, who became caliph in 705 A.D., increased the power of the caliphate, chose able ministers to rule under him, and was a generous patron of the arts. In Damascus, his capital, the Great Mosque was erected (in its present form) during his reign. Disorder at Constantinople enabled his troops to overrun Asia Minor, but his main military efforts were directed to establishing power in the farther East. His successor Suleiman opened an attack upon the Christian empire. The first onslaught was checked at Amorium, in the centre of Asia Minor, by the imperial general Leo (c. 680-741), called the Isaurian, of a race of mountaineers of eastern Asia Minor. Leo saw that the Saracens were not to be held back by isolated efforts ; there must be order at Constantinople if organized resistance was to be offered. From Amorium he hurried to Constantinople, where the reigning emperor was wise enough to abdicate. In 717 Leo was acclaimed emperor as Leo III.
Suleiman’s armies poured across Asia Minor ; his fleet dominated the Aegean Sea ; his troops were carried over to Europe, and Constantinople was shut in upon the west as well as upon the east. But through the winter Constantinople defied attack, and Leo’s ships, issuing from the Golden Horn, broke up the enemy fleet. As the spring of 718 advanced the Bulgarian king was induced to lend his aid. He attacked the Moslem force on the west, and inflicted upon it a great defeat. Leo himself had by this time dealt a heavy blow to the forces on the other side of the Dardanelles. The Saracens in Europe were hampered by failure of supplies, and the siege was raised; the remnants of the army were embarked in the fleet, and most of the fleet went to the bottom in a storm.
Islam’s Defeat in the East.
Leo’s great defence of Constantinople was decisive in the East. In following years the Saracens were expelled from Asia Minor, though the empire never effectively recovered territory beyond the Taurus mountains, Leo’s successors held what he had won. Rivalry between aspirants to the caliphate paralysed Islam. The Ommayad dynasty was overthrown and its place taken by the Abbasids about 750 ; the caliphate then acquired new splendour, with Baghdad instead of Damascus as its capital. Before that happened, however, the African Moslems, collectively called Moors, had planted in Spain a dominion that endured for nearly 800 years.
Moorish Invasion of Spain
The caliphate in the East had little or no control over the Moors. The Visigothic kings Spain had no better control over their nobles. In 711 a Moorish host crossed the Strait of Gibraltar (Jebel-Tarik, the mount of Tarik, who was the Moslem commander), annihilated the Visigothic army on the Guadalete, and overran the peninsula. The Goths were driven into the mountains and almost exterminated. Masters of Spain, and reinforced from Africa, the Moors a few years later poured through the Pyrenees into southern France; but in 732, somewhere between Tours and Poitiers (the battle is called by either name), they were shattered by the Franks under Charles Martel (the Hammer), who drove most of what was left of them back through the Pyrenees, which they never recrossed.
After this repulse of the Saracens the emperor Leo and his descendants ruled the Eastern empire with vigour and ability for some 60 years. They headed the iconoclastic movement (iconoclast means image-breaker) in an effort to purge the Church of image-worship, which they accounted idolatry; unfortunately, they destroyed vast numbers of statues. Their Reign ended when Irene, widow of Leo IV, usurped the imperial authority in 780. Throughout her regency for her son Constantine VI and her own reign (797-802) she was an ardent image worshipper, summoning the Second Council of Nicaea in 787 to reverse the decisions of the Council of Constantinople of 754 which had forbidden image worship.
The Franks were loyal to the line of the Merovings, though the kingdom was habitually divided between different members of the family, but that line had degenerated before the middle of the 7th century. Real government was carried on by an official with the title of mayor of the palace. This office became in effect hereditary in a warrior family from the Rhineland called the Arnulfings, of whom the most famous was Charles Martel. They extended Frankish rule over the Germans east of the Rhine, but although Charles drew the Franks together and delivered Western Christendom from the Mahomedan menace in 732 he was able to make the south secure only by hard fighting.
The puppet king died and no Merovingian heir was forthcoming ; Charles Martel refused the crown and continued to rule with the title of Duke of the Franks. In 741 he was succeeded by his two sons. Pepin the Short, and Carloman, who worked in harmony till Carloman retired into a monastery and left Pepin sole ruler in 747. The brothers found a young Merovingian prince, Childeric, in a monastery, and regularised their position by crowning him king of the Franks.
Pepin and the Papacy
For a hundred years the Papacy had been in conflict with the Lombards, who had produced only one memorable prince, Liutprand. Charles Martel was honoured and respected by successive Popes for his defence of Christendom and his zeal in Christening barbarian German tribes ; but he had turned a deaf ear to appeals for intervention against the Lombards. In 751 Pepin was elected king by the Franks gathered in a national assembly, but Childeric was the anointed king, and Frankish consciences required religious sanction for his deposition ; Pepin asked the Pope whether the royal title should not accompany exercise of the royal authority. In answer, Pope Stephen II crossed the Alps and at St. Denis crowned and anointed Pepin in 754. Later Popes claimed this as an admission that their authority extended to the deposition and appointment of kings, and founded upon that admission the temporal power of the mediaeval Papacy. Pepin could now no longer resist papal appeals for intervention against the Lombards, who had already annexed Ravenna and expelled the imperial exarch. Accordingly he descended on Italy, vanquished the Lombard king and compelled him to swear allegiance, handed over Ravenna and other recent Lombard conquests to the Papacy, and withdrew over the Alps to complete his work of consolidating his Frankish kingdom. Presently he expelled the last remnant of Saracens from Septimania, and brought to submission the rebellious dukes of Aquitaine on one side and Bavaria on the other. The kingdom he left to his sons in 768 was the largest and most powerful in Europe. It was divided between Charles and Carloman ; but after three years of quarrelling the death of Carloman in 771 left his brother Charles (Charlmagne) undisputed king of the Franks.