The Chinese navy has often been tasked to carry out expansionist policies. Admiral Zheng He is usually credited for commanding seven peaceful naval missions during the Ming dynasty to explore and set up trade with China's southern neighbors. However, in 1410, a Chinese fleet arrived in local waters near Sri Lanka seeking to establish Chinese power along the local maritime routes. When pirates, supported by the Kotte King Alakeshvara, attacked the Chinese ships a conflict broke out in southern Sri Lanka. During the Ming–Kotte war (1410–11), Admiral Zheng He and his troops invaded Kotte, conquered its capital, took its king and his family hostage, and brought them back to China. Eventually, the Yongle Emperor freed Alakeshvara, but when he got home a new pro-Chinese king had already taken the throne. Future Sri Lankan tribute missions to Beijing pledged their loyalty as part of China's extended tributary system. With Chinese power secured, Kotte pirates never again bothered a Ming treasure fleet.

Summary of the Ming–Kotte War

During the early years of the Ming dynasty, a deep-sea armada under Admiral Zheng He set sail in 1405 for a two-year voyage to the South China Sea and the Indian Ocean. In a total of seven expeditions that continued through 1433, these Chinese fleets visited Cochin, Siam, Java, Malacca, Sri Lanka, India, the Persian Gulf, and perhaps traveled as far south and west as southern Africa. Zheng He set up several strategic bases and trading centers during these voyages, most notably at Malacca, just up the Malaysian coastline from modern-day Singapore. As a result of his travels, many rare delicacies and strange animals were brought back to China.

These voyages are generally portrayed by the Chinese as peaceful. However, the Ming also used these voyages to claim land for China and to dominate local governments, which undermines descriptions of the voyages as nonmilitary expeditions. These early visits during the Ming, and claims that Chinese fishermen and fishing vessels were present in South China Sea waters for hundreds of years, have been used to date Chinese sovereignty over these disputed islands all the way back to the fifteenth century. Later, Communist historians argued that Zheng He stopped at the Paracel and Spratly Islands on his voyages, thus proving Chinese sovereignty there.