 Through the 8th and 9th centuries, the pointed arch was employed as standard in secular buildings in architecture throughout the Islamic world.The 10th century Aljafería at Zaragoza displays numerous forms of arch, including many pointed arches decorated and elaborated to a level of design sophistication not seen in Gothic architecture for a further two centuries.Increasing military and cultural contacts with the Muslim world, including the Norman conquest of Islamic Sicily between 1060 and 1090, the Crusades, beginning 1096, and the Islamic presence in Spain, may have influenced mediaeval Europe's adoption of the pointed arch, although this hypothesis remains controversial.