The origins are very obscure The Bedouin Arabs who were the original followers of Mohammed and responsible for the first islamic conquests in Syria Palestine and Persia were a nomadic people who lived in tents In the cities they conquered they began by converting old buildings and christian churches became mosques in damascus a pagan temple transformed into a Christian church was incorporated into the Great Mosque  The earliest and one of the most beautiful of islamic buildings is the Dome of the Rock Jerusalem built as a sanctuary not as a mosquetheres some debate about this on a circular plan  but much altered later especially in  when the exterior was cased in Persian tiles and the interior lined with marble The first minarets were converted church towers in Syria and that built a Kairouan Tunisia  is modelled on such a tower True to their nomadic origins the Umayyad rulers preferred desert residences to town palaces Several survive in ruins  Qasr alHair  Mshatta near Amman Jodania and Qasr atTuba in the Wadi Ghadorf near Amman In plan these groups of buildings were derived from Roman frontier stations Both religious and secular buildings of the period incorporate elements which were to become distinguishing features of islamic architecture The horseshoe arch tunnel vaults of stone and brick rich surface decoration in carved stone mosaic and painting During the Umayyad period the mosque took its permanent architectural for dictated by liturgical needs  minarets from which the faithful could be called to prayer a wide courtyard with a central fountain for ablutions with surrounding colonnades to give protection from the sun a large praying chamber marked externally by a dome as a sign of importance and internally by the mihrab or niche indicating the direction of Mecca towards which the faithful must turn in prayer The last survivor of the Umayyad dynasty became the founder of the Emirates at Cordoba in Spain where the early style of Islamic architecture was brought to perfection in the Great Mosque  Under the Abassids who surplanted the Umayyads in  Persian influence began to dominate the Islamic world The main achievements in architecture were the foundation of the new capital at Baghdad built on a circular plan  now largely destroyed and slightly later the smaller city of Raqqa Syria of which little survives except its richly decorated gateways It was at this period that Islamic architecture began to depart radically from Hellenistic and Byzantine conventions An elaborate court etiquette derived from persia and contrary to Bedouin ideas of informality was introduced and palaces were designed for the new caliphs on more formal and grandiose lines eg the palaces of Ukhaidir and Samarra in Iraq These large buildings were run up very quickly stone was abandoned in favour of brick and there was much use of decorative stucco The main C achievements were the great mosque of Kairouan Tunisia  the mosque of Bu Fatata Susa Tunisia  the Great Mosque of Samarra Iraq with its strange zigguratlike minaret c and the very well preserved mosque of Inb Tulun Cairo  Buidling materials were usually rough but dressed with intricate geometrical or floral surface decorations in painted stucco mosaic glazed tiles or shallow relief carving Local traditions influenced the decorative styles in various regions See Indian pakistan persian and turkish architecture In the original nucleus of the Islamic world the most notable later mosques are those a Tabriz Persia  Cairo Mosque of Sultan Barquq  and Isfahan Persia  Most of the earlier religious builings including the Masjidelaksa and the dome of the rock in jerusalem were also altered and more richly decorated in these centuries In southern spain a local style of great oppulence was developed its principle monuments are the Giralda tower Seville  and the Alhambra