Art History Resources for Students and Teachers
The art of Islam is unique in that it is not derivative from a specific location or tradition, rather it is based on the teachings of the religion, and stylistic elements are borrowed from the lands that were assimilated by the rapidly growing Muslim empire. Because of this, the characteristics of Islamic art share similarities with the art of eastern and western Europe, northern Africa, and western Asia. 
The religion of Islam began when the prophet Muhammad emigrated from Mecca to Modina, (present-day Saudi Arabia) in 622 CE. In less than ten years, Muhammad succeeded in uniting the fractured clans of Arabia under the rulership of Islam. After the death of Muhammad in 632, he appointed four caliphs, or successors to continue the spread of Islam. 
Under these caliphates, Islam gains territories along with converts with considerable speed. The breadth and depth of Muslim art can be categorized as follows:
Art During the Early Caliphates
The Umayyad Dynasty (661-750)
The Abbasid Dynasty (756-1031)
Later Islamic Art
The Seljuq Dynasty (1037-1194)
The Ottoman Empire (1299-1923)
The art of Islam is eclectic and sophisticated, comprised of painting, architecture, relief sculpture, textiles, domestic wares, and writing. Despite it's variation, there is the fundamental concept of aniconism that permeates every work of art, leading viewers to understand the reasoning for its construction in the first place. Because of this focus on non-figurative subject matter, all of Islamic art is characterized by geometric designs, arabesque line, and the incorporation of calligraphy. Islamic art uses variations of line, color and pattern, and knits together abstraction, organic form and script. During the Umayyad Dynasty, the earliest Muslim art consists of architecture, located where the political center of this dynasty settled, in Jerusalem. Located at this site is the oldest Muslim structure built, The Dome of the Rock. The plan of this building takes on the style of the centrally-planned Early Christian and Byzantine martyria, possessing the characteristic round or octagon-shaped formation, with the focus on, or planned around the center.

Dome of the Rock, Jerusalem, 688-691
San Vitale, Ravenna, Italy, 527-548
The central plan of Dome of the Rock shares structural characteristics with a number of Byzantine structures; the central plan was standard for many of the buildings erected in eastern Europe during the time of Justinian, after the capitol of the Roman Empire moved from Rome to Constantinople, later named Istanbul under the Ottoman Turks. 
The Dome of the Rock is a great monument to Islam, it is the third most holy site. The building, called the "Noble Sanctuary" marks the spot where Muhammad ascended into the presence of God, known as the "Night Journey". In contrast, the building of San Vitale, although similar in structure, was the palace chapel of Justinian I, one of the most important and successful emperors in Byzantine history. Inside the two structures, there are similar elements such as the ambulatory, and alternating piers and columns. San Vitale differs in the way that it includes a narthex, bell tower, and radiating chapels that branch off of the centrally-planned main structure. These elements connect the structure to the western Early Christian basilica, which share similar features. 
Close up view of the exterior tiling on Dome of the Rock
Interior apse mosaic of Christ Enthroned, San Vitale, Ravenna
Both structures are adorned with the same technique of mosaic. Using tessarae, or small tile-like pieces of ceramic or glass, designs or images can be created and rendered by using different colors. We can clearly see the difference between the subject matter and style of the two mosaics; the realistically rendered figurative composition of Christ enthroned, showing influence form Greco-Roman naturalism, whereas the tiled covering of the dome of the rock features elaborate geometric designs and calligraphy using vibrant colors. The exterior of the Dome of the Rock experienced destruction of the mosaic-covered exterior, and had to be restored in the 16th century with small glazed tiles.  The inside, however still contains original mosaics.
The structure of Islamic architecture shares other similarities to the West. The mosque, a sacred place of worship has similar elements to western Early Christian and Romanesque churches. There are variations of the mosque structure, mainly based on location; similar to the western adoption of the basilica and the eastern standard of the central plan of Christian buildings in the Roman Empire. The earliest mosques can be categorized into three general styles. The hypostyle mosque, the four-iwan mosque, and the central plan mosque. Besides the central plan, as discussed above, the hypostyle, or multi-columned mosque is comparable to the Early Christian structure of the basilica complex, as seen in the Old St. Peter's Basilica plan first built in 320-327 in Rome. We can compare this structure to a specific hypostyle mosque, the Great Mosque at Cordoba in Spain.
Diagram of Old St. Peter's Basilica, c. 320-327, Rome
Aerial view of the Great Mosque at Cordoba, begun in 784, Spain
When viewing both structures, we can see that both structures share a gateway, or wall in front of the courtyard, also known as an atrium in Roman architecture. Also, the entrance is marked by a tower or minaret. Also, both structures share a sacred focus on the eastern end of the structure, in the Early Christian basilica, the east end was were the altar was located, and behind that was a rounded niche called an apse. This area was the main focus of the church. In the mosque, the east end is marked by a mirhab, or niche indicating the direction of Mecca. The obvious differences include that the basilica structure beginning in Early Christian times incorporated the formation of the cross in the plan of the church by adding a transept that intersected with the end of the traditional basilica, and the interior of the basilica is characterized by a wide center isle called a nave, bordered by multi-columned side isles. The mosque interior is divided by rows of columns that dominate the entire inner structure. 
Another element that connects to both Romanesque and early Islamic mosques is relief sculpture. Romanesque cathedrals were adorned with sculpture that the illiterate could "read" and understand basic truths about the bible. It was also used to adorn the outside of the cathedral, becoming increasingly elaborate, until it reached its height in 12th and 13th century France during the Gothic period. Outward adornment of both mosques and cathedrals share this elaborate ornamentation, each in a unique style:
Frieze and detail of the facade of the Palace at Mshatta, Berlin Museum
Tympanum of the Abbey church of St. Pierre Moissac, France, 1125-1130
A final comparison that connects the art of Islam to the Western world is manuscript illumination. Script and writing were very important to the early Muslims because it was a source of embelishment; it was used to adorn sacred objects and structures, and the words of the Qur'an were sacred to early Muslims, just as the words of the Bible were sacred to early Christians. Early Islamic manuscripts were written using calligraphy,  predomoinantly the kufic script. The characters were bold and large, fitting only a few lines per page. Like Early Christian mauscripts, Islamic manuscripts were composed on parchment and vellum. Not until paper was introduced from China in the 8th century were there an introduction to more elaborate cusive script styles, the most widely used was the naskhi script. Like the Islamic manuscripts, Christian manuscripts were also charcterized by a variety of script and illumination styles, depending on time period and location. Below are examples of early manuscripts, one is in the Islamic, featuring the Kufic style from Iraq, and the other is an excerpt from the Vienna Genesis, the oldest surviving biblical codex, that illustrates the book of Genesis. 
Kufic Manuscript, c. 8-10th century
"Joseph's Departure" from the Vienna Genesis, c. 6th century, Syria
Looking at the two manuscripts, we can see that the focus is different on each. The kufic manuscript is expressive with the text itself, highlighted by the red accent marks. We can see that the sacred words are intended to remain in solitude, but also to communicate a rhythmic, pattern-like design. The Christian manuscript has a different focus, the illustration of what the text says becomes the focal point. The illustration is colored and rendered, projecting from the page, whereas the text is uniform and linear, blending into the purple background. The message of both texts are portrayed to be equally important, but we see a stark contrast between the aniconistic expression of the calligraphic script on the left and the focus on visual representation of the text through image on the right. 
Later manuscripts further this contrast, each become more elaborate and varied but increasingly deviate from each other in style:
Iskandar Namah [The Book of Alexander] by Nizami Ganjavi, c.1140-1200
Page showing the Four Gospels, Book of Kells, Dublin, c. 8th century
Despite the differences between Western and Islamic manuscript illumination, order is extremely important; both use geometric devices to organize the page. The art of Islam has served as a wonder and inspiration to many, and has even influenced artists who established their style directly from the principles of Islamic art.