The fall of Constantinople to the Ottoman Turks in 1453 marked the end of the Eastern Roman Empire, radically altering the political and trade environment in the Mediterranean. The traditional trade routes to the East through Asia Minor would be severely restricted for over a century, until the battle of Lepanto in 1571, which ended Turkish supremacy in the Mediterranean. The combination of piracy and heavy taxes levied by the Turks on merchant ships put the route to the Indies off limits to nearly all seafaring powers. Only the Venetians managed to preserve some control over trade flows. The Genoese, like the Portuguese and the Spanish, were forced to seek other routes. The first to seek an alternative route around the southern end of Africa was Henry the Navigator, Prince of Portugal (1394-1460). Using a new ship—the caravel—built to withstand ocean storms, the expeditions sponsored by Henry discovered the Azores, then sailed along the West African coast to Sierra Leone. That was in 1460. Some thirty years later, Bartolomeu Dias (ca. 1450-1500) rounded the Cape of Good Hope, and by the end of the century Vasco da Gama (1469-1524) had taken the first Portuguese ship to the East Indies.