Overview: China set out to dominate the seas. These new trade ventures were extremely lucrative, but after 30 years Ming bureaucrats forbade further voyages and abandoned maritime imperialism. Europe was torn by civil war, but the city states of northern Italy produced a cultural explosion known as the Renaissance. The Medici prince, Lorenzo the Magnificent, dominated and adorned Florence, nurturing painting, sculpture, poetry, music, and architecture. Greater than any European city was the Tenochtitlan, the Aztec capital on the site of what is now Mexico City. Built on marshland in Lake Texcoco, the highly organized city was supported by trade over huge distances, the Aztec gods placated by mass human sacrifice. The Ottomans took advantage of the weakness of the Byzantine empire, conquered Constantinople, and turned it into the capital of their empire. Mehmed the Conqueror's palace included a harem for 2.000 women, stables for 4.000 horses, 10 mosques, 14 baths and two hospitals. The kitchen could feed 5.000 or 10.000 on holidays. There were many great voyages of the 15th Century including that of Vasco de Gama's discovery of a route to the Indian Ocean and Christopher Columbus crossing the Atlantic and back.