Abu Bakr, dying in August, A.D. 634, was succeeded by Umar, or Omar, the conqueror of Syria, Persia, and Egypt by means of his generals Khalid bin Walid (the best, perhaps, that Islam produced), Abu Obaida, Mothanna, Sád bin Malik, Amr bin al-Aasi, and others. Omar himself was an early convert of A.D. 615, and a sudden conversion like our Paul; but one made his converts by fanaticism and the sword, the other by preaching and the pen. After a glorious and victorious reign of ten years Omar was assassinated by a Persian slave in November, A.D. 644, and was followed as Khalif by Othman, son of Affan, of the noble family of Abd-esh-Shems, who also assumed the title 'Amir al-Momenin, or Commander of the Faithful, which had been first adopted by his predecessor Omar. Othman ruled for twelve years, when he was murdered in A.D. 656, some say at the instigation of Ali, nephew of Muhammad, and husband of his only daughter Fatima. Anyhow, Ali succeeded Othman as Khalif, but was defeated by Moawia, Governor of Syria, and assassinated in A.D. 660.

Moawia bin Abu Sofyan then established the Benou Umayya dynasty, called by Europeans the Omaiyides, or Ommiades, from the name of Umayya, the father of the race. This dynasty reigned for nearly ninety years, and numbered fourteen successive princes, with their capital at Damascus.

During the reign of Yazid I., the second prince (A.D. 679-683), Hussain, the younger son of Ali the Khalif, came to an untimely end. His elder brother, Hasan, a man of quiet disposition, had been previously murdered by one of his wives, at the instigation, it is said, of Yazid before he came to the throne. This happened in A.D. 669. Later on Hussain, with his followers, rose in rebellion, and was killed on the plain of Kerbela, A.D. 680. The descendants, however, of this faction continued the disturbances which eventually brought about the great Muhammadan schism, and the splitting up of the religion into two sects, known to this day as the Sunnis and Shias. The adherents of the legitimate Khalifate, and of the orthodox doctrine, assumed the name of Sunnites, or Traditionists. These acknowledge the first four Khalifs (the rightly minded, or rightly directed, as they are called) to have been legitimate successors of Muhammad, while the sectaries of Ali are known as the Shiites, or Separatists. These last regard Ali as the first rightful Imam, for they prefer this title (found in Sura ii., verse 118, of the Koran) to that of Khalif. The Turks and Arabs are Sunnis: the Persians, and most of the Muhammadans of India, Shias.

This division into two sects, who hate each other cordially, has done more to weaken the power of the Muhammadan religion as a power than anything else. The Shias to this day execrate the memory of Yazid as the murderer of their hero Hussain, whom they have ever regarded as a martyr, and given full vent to their feelings on the subject in their 'Passion Play,' translated by Sir Lewis Pelly, and described by Mr. Benjamin in his 'Persia and the Persians.'

Other insurrections against the reigning Omaiyide Khalifs were also put down, portions of Asia, Africa and Spain conquered, and even France invaded, so that at the close of the Benou Umayya dynastry, about A.D. 750, their empire consisted of many and large territories in Europe, Africa and Asia. Their colour was white, as opposed to the black of the Abbasides, and the green of the Fatimites, as descendants of Muhammad.

But the Benou Umayya dynasty succumbed, A.D. 749, under the blows of Ibrahim (great-grandson of Abbas, the uncle of the Prophet), and of his younger brother, Abul Abbas, better known in history as As-Saffah, or the Blood-shedder. A decisive battle was fought on the banks of the river Zab, near Arbela, and Marwan II. (A.D. 744-750), the last of the Omaiyide Khalifs, was defeated, and fled first to Damascus, and then to Egypt, where he was eventually killed by his pursuers, A.D. 750.

The history of the reign of the Abbasides now begins, and under them the power and glory of Islam reached their highest point. But it is first necessary to allude to the conquest of Spain by the Omaiyides, a branch of which family still retained for a long time in the West the power which they had totally lost in the East.

The most important achievement of the reign of Walid I. (A.D. 705-715), the sixth prince of the Omaiyide dynasty, was the conquest of Spain by his generals Tarik and Musa. The Arabs (known in Europe under the name of Saracens) first established themselves in Cordova about A.D. 711, and the two generals above named continued their victorious progress throughout the country in 712 and 713, until nearly nine-tenths of the peninsula was held by the Muhammadans.

Some years later France even was invaded by the Arabs, and the banners of the Muslims were erected on the coasts of the Gulf of Lyons, on the walls of Narbonne, of Nimes, of Carcassonne, and of Béziers. The Arabs afterwards advanced as far as the plains of Tours, where their victorious progress was checked by Charles Martel, who gained a great victory over them near that town in October, A.D. 732, and completely defeated them, so that they were obliged to retire again to Spain. There successive viceroys and emirs ruled as the representatives of the Khalifs at Damascus until the fall of the Omaiyide dynasty in the East, A.D. 750.

But even after that Spain remained for many years under Arab domination. Anarchy almost prevailed from A.D. 750 to 755, but in that year the Arabs of Spain, weary of disorder, elected as their ruler Abd-ar-Rahman, grandson of the Khalif Hashim, tenth prince of the Omaiyide dynasty. At the time of his election, Abd-ar-Rahman was a wanderer in the desert, pursued by his enemies, when a deputation from Andalusia sought him out and offered him the Khalifate of Spain. It was gladly accepted. He landed there in September, A.D. 755, was universally welcomed, and founded at Cordova the Western Omaiyide Khalifate, which lasted up to A.D. 1031, under sixteen rulers, with certain interruptions during the reign of the last seven of them. On the extinction of the Khalifate, Spain was broken up into various petty kingdoms under kings and kinglets belonging to different Arab tribes and families. This continued from A.D. 1032 to 1092, when the Almoravides established themselves from A.D. 1092 to 1147, and were followed by the Almohades, who reigned up to A.D. 1232.