The Christian world today includes innumerable denominations and offshoots — which I sometimes refer to as the “isms” and schisms of Christianity. A few centuries ago, there was just the western Church and the eastern Church, and they weren’t all that different from each other. Then along came Martin Luther in the 16th century. The Lutheran separation from the Catholic Church was not the only one. There were others who went even further in giving up the Catholic practices. These various Protestant groups were generally called “reformed” churches. Three of the major ones had their beginnings in Switzerland.
One of these was the Presbyterian Church which was formed in Geneva under John Calvin. Another was the Reformed Church which Zwingli led in Zurich. Eventually, some of Zwingli’s followers took issue with the practice of infant baptism and their protests led to them being driven out of the Church. These protestors were called Anabaptists, meaning “over-again-baptizers” because they began to re-baptize adults who had already been baptized as infants. The name this third group called themselves was simply Baptist.
In addition to the baptism issue, the Baptists began to call for the separation of Church and State, calling into question the divine right of kings. This was highly unusual, and also highly unpopular in 16th and 17th century Europe. The Baptists were persecuted severely by both Catholics and Protestants. Many of these persecuted groups eventually found homes in the Netherlands and in the United States.
For a detailed timeline of the history of the Baptists, see http://www.reformedreader.org/btimline.htm