Human migration is a central theme in world and Asian history, but important cases, among them Chinese who emigrated to other countries between ca. 1000 and 1850 CE, have been somewhat neglected in the migration literature. Since the mid‐19th century, millions of Chinese migrated temporarily or permanently to other countries, making these migrants and their descendants a vital presence in the world economy and in the population of many nations. Today, more than 30 million people of Chinese ancestry or ethnicity live outside of Greater China, over 20 million of them in Southeast Asia. But this emigration has a much longer history, the subject of recent scholarly interest that has enriched our knowledge and is the focus of this essay. It has been said of the maritime trading and fishing peoples of southern China that they made fields from the sea. Enterprising and adaptable, Chinese have long sailed to Southeast Asia to trade, many of them settling permanently. By 1400, Chinese trade networks linked Southeast Asian trading ports to China and to each other. Chinese settlers eventually became dominant in the commercial sector in many societies, including most Western colonies, in Southeast Asia. Increasing numbers of migrants arrived to trade or mine for tin and gold, ushering in a “Chinese century” in the Southeast Asian economies from around 1700 into the mid‐1800s. Over the centuries some Chinese married local women, serving as cultural brokers between China and Southeast Asia and fostering hybrid communities. Others maintained their cultural heritage. After 1850, millions more left China. Chinese immigrants and their descendants built the foundations for a widespread modern diaspora and transnational connections. The emigrant flow from China continues, continuing a human behavior – migration – that has a long history in Asia.