We will analyze in this article the point of view of doctor Aziz Al Azmeh about Umayyad Caliphs in his book. He studied the origins of religions: judaïsm, christianism and islam. He demonstrated the role of umayyad caliphs to spread Islam by conquests or futuhât. Also, he explained that the umayyad state was created in the Shâm, a roman and byzantin political and cultural sphere. The caliph Mu’âwiya Ibn Abî Sufyân Ibn Harb had built a state with different institutions and very influenced by byzantin state (protocol, « bureaux », coins). And this state became an empire after conquests. The umayyad caliphs reinforced Islam by constructing mosques (the mosque of Qubbât Assâkhra in Jerusalem and the umayyad mosque in Damascus). In spite of these persian and byzantin influences, the umayyad state kept an arabic aspect (arabization of coins and institutions and ponctuation of Qurân in the period of al-Hajjâj Ibn Youssef). Finally, umayyad caliphs succeeded to strenghthen arab-islamic identity and the ideology of Khalifat Allah. It was necessary for their legitimacy.