The Ottoman Empire ruled over three continents for 623 years, beginning in 1299 after Osman Bey conquered many Anatolian principalities. The Empire came to exist when Mehmet the Conqueror took Istanbul in 1453, connecting Asia and Europe and ending the Middle Ages. It then expanded to North Africa under Selim I and reached as far as Vienna under Suleiman the Magnificent, governing large portions of Europe, Asia and Africa. The Empire constructed monuments across its lands and tolerated diverse religious and ethnic groups.