The foundation and rise of the Ottoman Empire is a period of history that started with the emergence of the Ottoman principality in c. 1299, and ended with the conquest of Constantinople on May 29, 1453. The rise of the Ottomans correlates with the decline of the Byzantine Empire. This period was characterized by the Byzantine-Ottoman Wars which lasted for a century and a half. The cause of Ottoman success cannot be attributed to any single factor, and they varied throughout the period as the Ottomans continually adapted to changing circumstances.