Cheng Ho (1371-ca. 1433) was a eunuch in the service of the Ming emperor Yung-lo and commander in chief of the Chinese expeditionary fleet to the South Seas in the early years of the 15th century.

Born into a family named Ma, presumably of Mongol-Arab origin, in central Yünnan Province, Cheng Ho was selected to be castrated by the general in charge of recruiting eunuchs for the court in 1381, when he was about 10. Assigned to the retinue of Chu Ti, who later became emperor, Cheng accompanied him on military campaigns, culminating in the usurpation of the throne by Chu Ti in 1402.

Because of a report that the former emperor Hui-ti had fled overseas, but probably with other good reasons, such as promoting Chinese influence or trade opportunities, Yung-lo sent out expeditions overseas under Cheng's command. In a period of 28 years, from 1405 to 1433, Cheng directed seven expeditions and...