Between 1405 and 1433, the Ming government sponsored a series of seven naval expeditions. The Yongle emperor designed them to establish a Chinese presence, impose imperial control over trade, impress foreign peoples in the Indian Ocean basin and extend the empire's tributary system. Zheng He was placed as the admiral in control of the huge fleet and armed forces that undertook these expeditions. Zheng He's first voyage consisted of a fleet of up to 317 ships holding almost 28,000 crewmen, with each ship housing up to 500 men. Zheng He's fleets visited Arabia, Brunei, East Africa, India, the Malay Archipelago and Thailand, dispensing and receiving goods along the way. Zheng He presented gifts of gold, silver, porcelain and silk; in return, China received such novelties as ostriches, zebras, camels, ivory and giraffes.