Fourth Voyage (1413-1415)
In late 1412, Cheng Ho was ordered by Zhu Di to make a fourth expedition. It wasn't until late 1413 or early 1414 that Cheng Ho embarked on his expedition with 63 ships and 28,560 men. The goal of this trip was to reach the Persian Gulf at Hormuz, known to be a city of amazing wealth and goods, including pearls and precious stones much coveted by the Chinese emperor. In the summer of 1415, the Treasure Fleet returned with a bounty of trade goods from the Persian Gulf. Detachments of this expedition sailed south along the eastern coast of Africa almost as far south as Mozambique. During each of Cheng Ho's voyages, he brought back diplomats from other countries or encouraged ambassadors to go to the capital Nanjing on their own.
Fifth Voyage (1417-1419)
The fifth voyage was ordered in 1416 to return the ambassadors who had arrived from other countries. The Treasure Fleet departed in 1417 and visited the Persian Gulf and the east coast of Africa, returning envoys along the way. They returned in 1419.
Sixth Voyage (1421-22)
A sixth voyage was launched in the spring of 1421 and visited Southeast Asia, India, the Persian Gulf, and Africa. By this time, Africa was considered China's "El Dorado," a source of riches. Cheng Ho returned in late 1421 but the remainder of the fleet didn't arrive in China until 1422.
Emperor Zhu Di died in 1424 and his son Zhu Gaozhi became emperor. He canceled the voyages of the Treasure Fleets and ordered ship builders and sailors to stop their work and return home. Cheng Ho was appointed military commander of Nanjing.
Seventh Voyage (1431-1433)
The leadership of Zhu Gaozhi did not last long - he died in 1426 at the age of 26. His son and Zhu Di's grandson Zhu Zhanji took Zhu Gaozhi's place. Zhu Zhanji was much more like his grandfather than his father was and in 1430 he resumed the Treasure Fleet voyages by ordering Cheng Ho to resume his duties as admiral and make a seventh voyage in an attempt to restore peaceful relations with the kingdoms of Malacca and Siam. It took a year to gear up for the voyage which departed as a large expedition with 100 ships and 27,500 men.
On the return trip in 1433 Cheng Ho is believed to have died; others state that he died in 1435 after the return to China. Nonetheless, the era of exploration for China was soon over as the following emperors prohibited trade and even the construction of ocean-going vessels.
It's likely that a detachment of one of Cheng Ho's fleets sailed to northern Australia during one of the seven voyages based upon the Chinese artifacts found as well as the oral history of the Aborigine.
After the seven voyages of Cheng Ho and the Treasure Fleets, Europeans began to make headway toward China. In 1488 Bartolomeu Dias rounded Africa's Cape of Good Hope, in 1498 Vasco da Gama reached China's favorite trading city of Calicut, and in 1521 Ferdinand Magellan finally reached Asia by sailing west. China's superiority in the Indian Ocean was unrivaled until the 16th century when the Portuguese arrived and established their colonies along the rim of the Indian Ocean.
