The term Islamic art not only describes the art created specifically in the service of the Muslim faith (for example, a mosque and its furnishings) but also characterizes the art and architecture historically produced in the lands ruled by Muslims, produced for Muslim patrons, or created by Muslim artists. As it is not only a religion but a way of life, Islam fostered the development of a distinctive culture with its own unique artistic language that is reflected in art and architecture throughout the Muslim world.
The lands newly conquered by the Muslims had their own preexisting artistic traditions and, initially at least, those artists who had worked under Byzantine or Sasanian patronage continued to work in their own indigenous styles but for Muslim patrons. The first examples of Islamic art therefore rely on earlier techniques, styles, and forms reflecting this blending of classical and Iranian decorative themes and motifs. Even religious monuments erected under Umayyad patronage that have a clearly Islamic function and meaning, such as the Dome of the Rock in Jerusalem, demonstrate this amalgam of Greco-Roman, Byzantine, and Sasanian elements. Only gradually, under the impact of the Muslim faith and nascent Islamic state, did a uniquely Islamic art emerge. The rule of the Umayyad caliphate (661–750) is often considered to be the formative period in Islamic art. One method of classifying Islamic art, used in the Islamic galleries at the Metropolitan Museum, is according to the dynasty reigning when the work of art was produced. This type of periodization follows the general precepts of Islamic history, which is divided into and punctuated by the rule of various dynasties, beginning with the Umayyad and ‘Abbasid dynasties that governed a vast and unified Islamic state, and concluding with the more regional, though powerful, dynasties such as the Safavids, Ottomans, and Mughals.
With its geographic spread and long history, Islamic art was inevitably subject to a wide range of regional and even national styles and influences as well as changes within the various periods of its development. It is all the more remarkable then that, even under these circumstances, Islamic art has always retained its intrinsic quality and unique identity. Just as the religion of Islam embodies a way of life and serves as a cohesive force among ethnically and culturally diverse peoples, the art produced by and for Muslim societies has basic identifying and unifying characteristics. Perhaps the most salient of these is the predilection for all-over surface decoration. The four basic components of Islamic ornament are calligraphy, vegetal patterns, geometric patterns, and figural representation.