The Ottoman Empire was located primarily in southeastern Europe, western Asia, and northern Africa. It originated in northwestern Anatolia (modern-day Turkey) around 1299, founded by Osman I. Over centuries, it expanded to cover much of the Balkans, the Middle East, including parts of the Arabian Peninsula, and North Africa. The empire's capital was Constantinople (modern- day Istanbul) from 1453 after it was conquered by Mehmed II. At its peak, the Ottoman Empire spanned parts of three continents: Europe, Asia, and Africa, controlling regions that are now part of many modern countries including Turkey, Greece, Egypt, Saudi Arabia, and others.