Constantinople was the newfound Christian capital of the Eastern Roman Empire, otherwise known as the Byzantine Empire. Throughout its long history, there have been many different attacks against the religious capital. For a period of 1123 years, Constantinople was a solid Byzantine-controlled city, apart from a few minor upheavals. Numerous attacks and sieges were attempted to overthrow the city, but most failed miserably. It was only in 1453 that the city finally fell to the Ottoman Empire. Some Byzantine victories may have been caused by a weapon called Greek fire, believed to have been invented around 650 AD (Groller). The weapon was similar to today's weapon, napalm. Of the numerous sieges against Constantinople, the two Arab sieges, of 674–678 AD and 717–718 AD respectively, were one of the greatest victories for the Byzantine Empire. During the First Arab-Byzantine War, the Byzantine leader Constantine IV defended Constantinople causing the Byzantines to achieve victory with the help of Kallinikos, a Syrian Christian refugee, who created the Greek firearm (WorldLingo). The weapon, being new, was extremely effective. During the second siege, the Arabs attempted to retake the city and had an army of approximately 180,000 men, with approximately 2,560 ships. Greek fire was used again, to great effect. It is assumed that the weapon has become standard use for land and sea. The Byzantines, with the help of the Bulgarians, defeated the Arabs in less than two years. The city may have fallen without the help of the Bulgarians, and the Byzantines were grateful, but a man named Norwich claims that the Bulgarians had the real reason to help them. The Bulgarians had no love for the Byzantines, but were determined that if Co. ..... half of the document ......ducation group, inc.. Retrieved November 22, 2010, from http://web.ebscohost .com/ehost/detail?vid=1&hid=7&sid=4233fc61-b90d -4ed7- 8040- 1dc021457455%40sessionmgr10&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d #db=funk&AN=BY219000Latter-Rain, initials. (n.d.). The Fourth Crusade: Sack of Constantinople. Retrieved from http://latter-rain.com/crusade/curfor.htmLuttwak, Edward. (2009). The grand strategy of the Byzantine Empire. Boston, Massachusetts: Belknap Press of Harvard University Press.Spiritus-Temporis. Mehmed II. (2002). Retrieved from http://www.spiritus-temporis.com/mehmed-ii/Vailhé, S. (2009). Constantinople. New advent. Retrieved November 28, 2010, from http://www.newadvent.org/cathen/04301a.htmWorldLingo, Initials. (n.d.). Siege of Constantinople (718). Retrieved from http://www.worldlingo.com/ma/enwiki/en/Siege_of_Constantinople_(718)