But, the unsuccessful attack of Constantinople in 717 AD destabilized the realm.
The Abbasid Cliphate (750-1258 AD) shifted the capital from Damascus to Baghdad. In Abbassid Dynasty, Spain and much of Africa did not come under the rule of Abbasid and self-governing empires came up in the east of the Abbasid Empire. The Abbasid Caliphs spent their days in idle leisure which brought the period of conquests to an end. Again, from 756 AD to 929 AD, Umayyad Dynasty was resumed in Spain (Andalus).
The Ottoman Turks conquered Constantinople on 29 May, 1953 and it became the new capital of the Ottoman Empire. Mehmed I had to face much criticism when he proposed to assault Constantinople in 1952. The Ottoman Court disapproved of Mehmed’s confidence in his abilities and blamed him for being too rash. Mehmed had the European Castle constructed at the Bosphorus shore and began moving his troops to surround the city of Constantinople. He gave an ultimatum to the Byzantine emperor Constantine XI to admit defeat which he declined. Thus, the siege began which lead to the fall of Constantinople on May 29,