Persecution made the Mennonites a migrating people, moving from the Low Countries and Switzerland into Prussia, Russia, and then across the Atlantic to North and South America in successive waves, so that today the tradition is spread across the globe. It is also internally diverse, ranging from conservative groups such as the Old Order Mennonites, who, like their Amish cousins (who separated from the Mennonites in 1693), limit the use of modern technology and keep a distinct plain dress and lifestyle, to fully assimilated, theologically liberal congregations indistinguishable in outward life from their neighbours. Most Mennonites fall between these poles. The tradition has become widely known for its peace witness and for practical service: conscientious objection to war, disaster relief and development work through bodies such as the Mennonite Central Committee, and a strong ethic of mutual aid.
Worldwide membership, coordinated loosely through Mennonite World Conference, numbers well over a million and, in a striking reversal of the tradition's European origins, is now concentrated in Africa, Asia and Latin America as much as in North America and Europe. Scholars group the Mennonites, with the Amish, Hutterites and Brethren in Christ, as the principal surviving heirs of the Anabaptist reformation.