[B Knotts]

I suspected you would cite those groups. However, those were heretical groups, doctrinally unrelated to the Anabaptists, at least according to many authorities, including anabaptists.org:

Before telling the story of how the Mennonite Church began, it is necessary to enumerate a number of false theories of its origin. Some historians have imagined a connection between the radical Zwickau Prophets or the fanatical Thomas Muenzer and the founders of the Mennonite Church. But for this supposed connection there is not historical foundation. Other historians have gone astray in seeking to account for the rise of the Mennonite Church by interpreting the movement as a revolt of the lower classes. This social-economic theory is also unsupported by the facts. Indeed the chief founder of the Mennonite Church was the university-trained son of a rich family. The early leaders of the church did not preach social revolt; they proclaimed repentance and baptism. Another unsound theory is that the movement arose under the influence of Catholic monastic orders. A much less harmless theory but one that is also without historical support is that of Apostolic succession. According the this theory there has been a continuity of organization in small groups outside the Catholic church from A.D. 30 to 1525. Actually these non-Catholic groups differed widely from each other; all held some heretical views and in many cases had no connection with each other. Finally, there have been those who thought that the Mennonite Church was of Waldensian origin. Actually the Waldenses disappeared in Switzerland a century before the rise of the Anabaptist movement. (from The Anabaptist Story, William R. Estep, 1975)

[DannyTN]

I don't know enough about the groups to say whether they held heretical ideas or not. I've just always heard that there were always groups outside of the Catholic church that studied the scriptures for themselves. And these ranged from organized groups to individuals and hermits.

Indeed, if you read the book of the Martyrs, you read about communities that were persecuted by Rome because they were reading and studying the scriptures for themselves.

I think there have always been Christians both outside and inside of the Roman Catholics.

And it is really not surprising that the protestants split as corrupt as the church had become at the time. It was Rome that had left the Gospel, not the Protestants that left the church.