Islamic glass is often indistinguishable from late Classical/Byzantine and Sassanian models. The advent of Islam in the seventh century and the creation of a vast political empire did not have an immediate impact on the practices of glass-making workshops that had existed for centuries, especially in the Eastern Mediterranean coastal regions. In the Eastern Mediterranean Classical-Byzantine forms and techniques continued to be practiced, whilst further east Parthian-Sassanian traditions prevailed. By the late eighth century however it is possible to discern a distinctively Islamic style of glass. Following the rise of the Abbasid Caliphate in 750 CE, the capital of the Islamic world was moved from Levantine Damascus to Baghdad in Mesopotamia. This led to a cultural shift away from the influences of Classical traditions, and allowed for the development of an more pure Islamic expression. Cultural ties across the empire and the migration of craftsmen from one area to another helped to fuse Classical and Near-Eastern traditions. Whilst it is certainly true that one of the characteristic features of Islamic glass is the emphasis on decoration, undecorated vessels of great beauty were also created. Many of these were used for everyday purposes by the urban population- as tableware, containers for oils and perfumes, storage vessels, oil lamps and even for scientific and medicinal equipment.