The military and cultural contacts with the medieval Islamic world, including the Norman conquest of Islamic Sicily in 1090, the Crusades (beginning 1096), and the Islamic presence in Spain, may have influenced Medieval Europe's adoption of the pointed arch. Another feature of Gothic architecture, a kind of rib vault, had also earlier appeared in Islamic architecture, and spread to Western Europe via Islamic Spain and Sicily. The early rib vaults in Spain were used to support cupolas, and were decorative. The dome of the Mosque-Cathedral of Cordoba was supported by pendentives, rather than the vault. These were frequently used in Romanesque and Byzantine architecture, as in the dome of Hagia Sophia in Istanbul, which also was supported by pendentives. The Gothic rib vault, among other features, such as the flying buttress, have their antecedents in Romanesque architecture, such as Durham Cathedral, constructed between 1093 and 1096.