There were always other groups like the anabaptists that rejected the Roman Pope and Catholic hierarchy. Below is an excerpt of non-catholic church history from the following link. Church History
During all this time of the rise and development of false doctrines and practice in the churches, there were scattered through Europe, Asia, and Africa, groups of dissenting churches which refused to acknowledge the Roman pope and sought to follow the New Testament. Some early groups were the Montanists, Novatians, and Donatists. Later groups included the Petrobrusians, Waldensees, and Anabaptists. Catholic historians call most of these sects "Anabaptists". They were mercilessly persecuted throughout the centuries until after the Reformation, and some persecution against them has continued to modern times.
Though these groups did not carry the name "Baptists", many of them did hold various Baptist tenents, such as separation of church and state, spiritual democracy, salvation by grace apart from sacraments, believers' baptism, and immersion as the mode of baptism. churches holding these truths cherished New Testament principles. They shared with Baptists the desire to follow Christ's will for His churches.
When the Reformation came, numerous new non-Catholic groups appeared. Some of them became the large Protestant denominations of today. They all rejected many of the heresies of the Roman Catholic Church, but most of them retained some teachings which had no foundation in the New Testament. In the centuries since the Reformation, other denominations have been formed until there are now hundreds of separate denominational organizations. Some of them have departed far from using the New Testament as their only rule of faith and practice.
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)