Mennonites are groups of Anabaptist Christian church communities of denominations. The name is derived from one of the early prominent leaders of the Dutch Anabaptist movement, Menno Simons (1496–1561) of Friesland. Through his writings about Reformed Christianity during the Radical Reformation, Simons articulated and formalized the teachings of earlier Swiss founders, with the early teachings of the Mennonites founded on the belief in both the mission and ministry of Jesus, which the original Anabaptist followers held with great conviction, despite persecution by various Roman Catholic and Mainline Protestant states.  The Mennonite World Conference was founded at the first conference in Basel, Switzerland, in 1925 to celebrate the 400th anniversary of Anabaptism