One of the most successful denominations in my homeland of Wales was the Calvinistic Methodists. (Yes, I know that sounds like an oxymoron.) In the 19th century, these Methodists launched missionary work among the Mizo people in northeastern India and were so effective that today almost 90 percent of the Mizos are Christian. In 2006 the flourishing Mizo church began returning the favor—it sent two missionaries to reconvert Wales.

Any account of modern Asian Christianity must deal with minority peoples like the Mizo, who long occupied a marginal status in the European empires and the post-imperial states. Such groups are sometimes labeled “tribal,” which encourages us to dismiss them as primitive and irrelevant. Recently, though, scholars have devised a new category for these minorities, and their work is extraordinarily valuable for understanding the history of Christian mission.

In 2002 Dutch historian Willem van Schendel noticed the broad similarities that united minority peoples spread across vast tracts of south and southeast Asia, even though these groups had no direct connections to each other. These peoples usually lived in remote or upland areas and were separated from the great mainstream civilizations of the lowlands for reasons of language, religion, social organization, and economic life. Examples of such peoples would include India’s Nagas and Mizos, the Hmong of Vietnam and Laos, and the Karen and Chin in Myanmar. Taking a Tibeto-Burman name for a barbarous highlander, zomi, van Schendel suggested that all these peoples belonged to a region he christened “Zomia.”