Though the Amish take their name from Jakob Amman their history is much deeper than Amman. The term Amish was first used as a schandename (a term of disgrace) in 1710 by opponents of Jakob Amman. The first division between Swiss Brethren was recorded in the 17th century between Oberländers (those among the hills) and Emmentaler (those living in the Emmetal valley). The Oberländers were a more extreme congregation; their zeal pushing them into more remote areas and their solitude making them more zealous.
Swiss Anabaptism developed, from this point, in two parallel streams. Those following Amman became known as Amish or Amish Mennonite. The others eventually formed the basis of the Swiss Mennonite Conference. Because of this common heritage, Amish and Mennonites retain many similarities. Those who leave the Amish fold tend to join various congregations of Conservative Mennonites. -wiki