The Umayyads continued the Muslim conquests, incorporating the Transoxiana, Sindh, the Maghreb and the Iberian Peninsula (Al-Andalus) into the Muslim world. At its greatest extent, the Umayyad Caliphate covered , making it one of the largest empires in history in terms of area. The dynasty was eventually overthrown by a rebellion led by the Abbasids in 750. Survivors of the dynasty established themselves in Cordoba which, in the form of an emirate and then a caliphate, became a world centre of science, medicine, philosophy and invention, ushering in the period of the Golden Age of Islam.