Religious persecution
The Mennonite movement was founded by Menno Simons, a Frisian priest who left the Roman Catholic Church in 1536 and became a leader within the Anabaptist movement. The Low Countries regions of Friesland and Flanders, as well as Eastern Frisia and Holstein, became a center of the Mennonites. Religious persecution in the Low Countries under Fernando Álvarez de Toledo, 3rd Duke of Alba, forced many Mennonites to leave in the 16th century.