Christianity and Islam are two of the most widespread religions in the world. Both religions once founded were not accepted by the people of that time and faced great resistance. Early Islamic art and early Christian art are both historically important as both are similar in some ways. The oldest architecture and first such structure of Muslims is the Dome of the Rock located in Jerusalem. When Muslims conquered the city of Jerusalem in 1940, they needed a place (the Mosque) to worship and offer their prayers in congregation. At the same time they also wanted to build a monument showing the success of Muslims and their religion, Islam. Likewise, Christians built their churches and monuments to show their influence and selected sites that were former pagan temples and catacombs to build their churches. The Muslims had already conquered Syria and the Byzantines and so used their designs to build the Dome of the Rock. The Santa Costanza was originally built in Rome, Italy, in 360c. It was built for Constantine's daughter, but was later transformed into a memorial church. Scholars now argue that Santa Costanza was originally built for Constantine's sister, Helina. Both of these structures are similar in their function and used the central plan to focus on the center. Looking at both structures, the Dome of the Rock and the Holy Constance, the viewer can understand that both are similar as they both have circular domes. The most notable difference in both structures is that of shape, external appearance and design. Santa Costanza now appears simple in such a way that it is not decorated from the outside like...half of a sheet of paper.......html (accessed 22 April 2014). Ettinghausen, Richard, Oleg Grabar, and Sheila Blair. The art and architecture of Islam 650-1250. Harmondsworth, Middlesex, England: Penguin Books, 1987. Fazio, Michael W., Marian Moffett, and Lawrence Wodehouse. A world history of architecture. 2nd ed. Boston: McGraw-Hill, 2008.Glancey, Jonathan. The history of architecture. London: Dorling Kindersley, 2000.Glancey, Jonathan. Architecture. London: DK, 2006. Hillenbrand, Robert. "The Birth of Islamic Art: The Umayyads". In Islamic art and architecture. Holberton, Paul. The world of architecture. New York: Crescent Books:, 1988. "Images of Santa Costanza, Rome." Images of Santa Costanza, Rome. http://www.bluffton.edu/~sullivanm/italy/rome/costanza/costanza.html (accessed 21 April 2014). Krautheimer, Richard. Early Christian and Byzantine architecture. Baltimore: Penguin Books, 1965.