The Ottoman Empire began as a small Turkish principality in Anatolia around 1299 CE and grew over the following centuries into one of the most powerful and long-lasting Muslim empires in history. A pivotal moment came in 1453 CE, when Sultan Mehmed II conquered Constantinople, ending the Byzantine Empire and establishing the city, renamed Istanbul, as the Ottoman capital. At its height in the sixteenth and seventeenth centuries under rulers such as Suleiman the Magnificent, the empire spanned three continents, controlling much of Southeast Europe, the Middle East, and North Africa, including the holy cities of Makkah and Madinah. In 1517, after conquering the Mamluk Sultanate of Egypt, the Ottoman sultans also assumed the title of caliph, positioning themselves as leaders of the wider Sunni Muslim world alongside their political rule, a religious dimension that grew more prominent in later centuries. The Ottomans built sophisticated legal, administrative, and educational systems and were notable patrons of architecture, exemplified by the work of the chief architect Mimar Sinan. Following defeat in the First World War and the collapse of the empire, the Ottoman sultanate was abolished in 1922, and the caliphate itself was formally abolished in 1924 by the new Turkish Republic under Mustafa Kemal Ataturk, ending the last widely recognized Muslim caliphate.
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