Key leader was Jacob Ammann. See distinctive characteristics they shared with Anabaptists.
Copyright: Dictionary source: Theological and Philosophical Biography and Dictionary
English to English translation of Amish amish \am"ish\ (?), n. pl. [written also omish.] (eccl. hist.) the amish mennonites. amish \am"ish\, a. [written also omish.] (eccl. hist.) of, pertaining to, or designating, the followers of jacob amman, a strict mennonite of the 17th century, who even proscribed the use of buttons and shaving as "worldly conformity". there are several branches of amish mennonites in the united states.
The Amish (; Pennsylvania Dutch: Amisch, ) are a group of traditionalist Christian church fellowships, closely related to but distinct from Mennonite churches, with whom they share Swiss Anabaptist origins. The Amish are known for simple living, plain dress, and reluctance to adopt many conveniences of modern technology. The history of the Amish church began with a schism in Switzerland within a group of Swiss and Alsatian Anabaptists in 1693 led by Jakob Ammann. Those who followed Ammann became known as Amish.