Between 1405 and 1433, the Ming government sponsored a series of seven naval expeditions. Emperor Yongle designed them to establish a Chinese presence, impose imperial control over trade, and impress foreign peoples in the Indian Ocean basin. He also might have wanted to extend the tributary system, by which Chinese dynasties traditionally recognized foreign peoples.

I was placed as the admiral in control of the huge fleet and armed forces that undertook these expeditions. My first voyage consisted of a fleet of perhaps 300 ships holding almost 28,000 crewmen. These were probably mainly large six-masted ships - it is now thought that the large and flat nine-masted "treasure ships" were probably river ships used by the Emperor.
On the first three voyages, I visited southeast Asia, India, and Ceylon (Sri Lanka). The fourth expedition went to the Persian Gulf and Arabia, and later expeditions ventured down the east African coast, as far as Malindi (Kenya). Throughout his travels, I liberally dispensed Chinese gifts of silk, porcelain, and other goods. In return, I received rich and unusual presents from his hosts, including African zebras and giraffes that ended their days in the Ming imperial zoo. My company and I paid respects to local deities and customs, and in Ceylon they erected a monument honouring Buddha, Allah, and Vishnu.

I generally sought to attain my goals through diplomacy, and my large army awed most would-be enemies into submission. I ruthlessly suppressed pirates who had long plagued Chinese and southeast Asian waters. He also intervened in a civil disturbance in order to establish my authority in Ceylon, and I made displays of military force when local officials threatened my fleet in Arabia and East Africa. From my fourth voyage, I brought envoys from thirty states who traveled to China and paid their respects at the Ming court.

In 1424, the Yongle Emperor died. His successor, the Hongxi Emperor (reigned 1424–1425), decided to curb the influence at court. I made one more voyage under the Xuande Emperor (reigned 1426–1435), but after that Chinese treasure ship fleets ended. I died during the treasure fleet's last voyage.

On my seven voyages, I successfully relocated large numbers of Chinese Muslims to Malacca, Palembang, Surabaya and other places and Malacca became the center of Islamic learning and also a large international Islamic trade center of the southern seas.
My missions showed impressive demonstrations of organizational capability and technological might, but did not lead to significant trade, since I was an admiral and an official, not a merchant. Chinese merchants continued to trade in Japan and southeast Asia, but Imperial officials gave up any plans to maintain a Chinese presence in the Indian Ocean and even destroyed most of the nautical charts that I had carefully prepared. The decommissioned treasure ships sat in harbors until they rotted away, and Chinese craftsmen forgot the technology of building such large vessels.