The Great Mosque of Kairouan (in Tunisia), considered as the ancestor of all the mosques in the western Islamic world , is one of the best preserved and most significant examples of early great mosques. The Great Mosque of Kairouan is constituted of a massive square minaret, a large courtyard surrounded by porticos and a huge hypostyle prayer hall covered on its axis by two cupolas.
The Great Mosque of Samarra in Iraq, completed in 847 AD, combined the hypostyle architecture of rows of columns supporting a flat base above which a huge spiraling minaret was constructed.
The Hagia Sophia in Istanbul also influenced Islamic architecture. When the Ottomans captured the city from the Byzantines, they converted the basilica to a mosque (now a museum) and incorporated Byzantine architectural elements into their own work (e.g. domes). The Hagia Sophia also served as a model for many Ottoman mosques such as the Shehzade Mosque, the Suleiman Mosque, and the Rüstem Pasha Mosque.
Distinguishing motifs of Islamic architecture have always been ordered repetition, radiating structures, and rhythmic, metric patterns. In this respect, fractal geometry has been a key utility, especially for mosques and palaces. Other significant features employed as motifs include columns, piers and arches, organized and interwoven with alternating sequences of niches and colonnettes. The role of domes in Islamic architecture has been considerable. Its usage spans centuries, first appearing in 691 with the construction of the Dome of the Rock, and recurring even up until the 17th century with the Taj Mahal. As late as the 19th century, Islamic domes had been incorporated into Western architecture.
