During the 16th and 17th centuries, at the height of its power, under the reign of Suleiman the Magnificent, the Ottoman Empire was a multinational, multilingual empire controlling most of Southeastern Europe, Central Europe, Western Asia, parts of Eastern Europe, the Caucasus, Northern Africa, and the Horn of Africa.It is believed that the Ottoman Empire was able to grow so rapidly because other countries were weak and unorganized, and also because the Ottomans had advanced military organization and tactics for the time.