The Ottoman Empire was an imperial state that lasted from 1299 to 1922. In 1453, Mehmed the Conqueror captured Constantinople and made it his capital. During the 16th and 17th centuries, in particular at the height of its power under the reign of Suleiman the Magnificent, the Ottoman Empire was a powerful multinational, multilingual empire, which invaded and colonized much of Southeast Europe, Western Asia, the Caucasus, North Africa, and the Horn of Africa. Its repeated invasions, and brutal treatment of Slavs led to the Great Migrations of the Serbs to escape persecution. At the beginning of the 17th century the empire contained 32 provinces and numerous vassal states. Some of these were later absorbed into the empire, while others were granted various types of autonomy during the course of centuries.