Islamic architecture has evolved within Muslim culture in the course of the history of Islam. Therefore the term encompasses religious buildings as well as secular ones, historic as well as modern expressions, and all other structures that come under the varying levels of Islamic influence.
A specific Islamic architectural style started to develop soon after the Prophet Muhammad (PBUH). The style of early Islamic architecture grew from Roman, Egyptian, Persian, and Byzantine styles from the beginning. The completion of Dome of the Rock in AD 691 in Jerusalem can be identified an early example. The Dome featured interior vaulted spaces, a circular dome, and the use of repeating geometric and decorative patterns. The influence of the architectural and decorative styles of pre-Islamic Persia also became prominent. The Turks and the Mongols also brought in Central Asian influences on styles and thus, themes from one area soon became universal in the vast Islamic world.
Islamic architecture, like Jewish and Christian architecture, is designed to interpret the various teachings of the faith. Repeating themes which suggest infinity symbolize the concept of Allah's infinite power. Islamic religious art stays away from sculptures or figural decorations because it is regarded as an act of idolatry. Figural art does exist in the general cultural environment of the places where Islam is the dominant faith. However, it is practically never used in an orthodox religious building. Instead, arabic calligraphy developed as an art form both to communicate and symbolize faith, together with patterns and designs based on geometry and the arabesque. Calligraphy is used to enhance the interior of a building by providing quotations from the Qur'an. Impressive structures such as large domes, towering minarets, and large courtyards and are also used in Islamic architecture are intended to convey power. The most prominent feature of Islamic architecture is the focus on the interior of structures as opposed to the outside. Islamic architecture has been called the "architecture of the veil" because the beauty lies in the interior which are not visible from the outside.
In Architecture of the Islamic World, Ernst J. Grube writes that the dominant form of true Islamic architecture is the hidden architecture. In other words, it is architecture that must be experienced by being entered and seen from within.
Enclosed space and vaults are the most important element of Islamic architecture, according to Grube. With the exception of the dome and the entrance portal, decoration in Islamic architecture is used to beautify and express the religious atmosphere in the interior. He writes, "Decorations in a mosque range from the use of mosaic and painted decoration to tiles, especially luster and painted polychrome, and from molded and deeply cut stone or plaster to actual openwork and pierced...