To begin with it can be said that features of Islam facilitated its spread among the Arabs. In combat, overcoming the resistance of the tribal aristocracy, prone to separatism (the revolt of tribes Arabia after the death of Muhammad), Islam became the Arab’s dominant religion. The new religion pointed warlike Bedouins clear and simple way to enrich, to resolve the crisis ”“ the conquest of new territories. The successors of Muhammad – Caliphs Abu Bakr, Omar, Osman – in a short time conquer neighbor, and then more distant countries of the Mediterranean and Middle Asia regions. These conquests were perpetrated under the banner of Islam ”“ “a green flag of the Prophet”¯.
It is essential to note that the countries, conquered by the Arab’s conscription of the peasant population were significantly alleviated, especially for those, who accepted Islam and this facilitated a shift of the broad masses of the population of different nationalities into a new religion. Islam was founded as the national religion of the Arabs, but soon began to turn into a supranational, global religion. In the VII-IX centuries Islam became the dominant and almost the only religion in the countries of the caliphate that has engulfed a huge area – from Spain to Central Asia and the borders of India, according to A Concise History of Islam and the Arabs (2010).
As a matter of fact, the military successes of the Omayyad and then Abbasids caliphates can be explained by the Arab relation to the war. In other words, Arabs called their opponents as religion enemies and declared them so-called “holy war”¯. In 633 squad troops under the command of Khalid ibn al-Walid with the Bedouins of North-Eastern Arabia took the city of Hira (Southern Iraq). In the same year in Palestine and Syria invaded three squad of Arab tribal army. In turn, weak Byzantine army was defeated by Arabs in Wadi and its remnants were destroyed in 634 in Daxing. After 6 months of the siege of Damascus, in September 635, it was surrendered to the Arabs. The news of the movement of the Byzantine army (50.000 soldiers), formed by Emperor Heraclius in Edessa, aroused retreat of Khalid Hira near Damascus. However, on August 20, 636 the Byzantine army was completely routed by the Arabs. After that, the Arabs again occupied Damascus and other cities in Syria and after the occupation of Jerusalem in 638 and Caesarea in 640 all Syria and Palestine came under their authority, according to Richard A Gabriel (2007).
In Iraq, after the capture of Hira Arab troops suffered several defeats from the Iranian Sassanid troops and were forced to retreat from conquered territory. However, in the early summer of 637 Arabs, who have received reinforcements, defeated the Iranian army at the Battle of Qadissiya and occupied the Sassanid – the capital of Ctesiphon Iran. Also, in 641 Arab troops took Mosul and in 642 at Nehavenda won a decisive victory over the Iranian forces of Yezdegerda III. After that, the resistance of Iranian forces was scattered, according to World of Islam (2009).
Islam, as dominant religion, was initially developed in the Arabian Peninsula in an environment of disparate Arab tribes, managed to unite them and gave a powerful impetus to the development of Arab civilization. After embracing Islam the Arabs conquered vast territories, where the main religion was Islam. In other countries, Islam came peacefully and won the hearts of millions of people. Arab culture has integrated many nations: Arabs, Persians, Egyptians, etc. The main difference between Islam from other religions is that it is completely blended spiritual and secular power, and there is no cohesive religious organization, as in Christianity or Buddhism. Becoming an integral part of human life, Islam directed Arabs in their actions for many years.