Reformed and Presbyterian churches are one of the main branches of Protestant Christianity. They were founded in Switzerland in the 16th century by Huldrych Zwingli and John Calvin.
Zwingli and Calvin were strongly influenced by Renaissance humanism, late medieval nominalism, and lay communities practicing mysticism. Many social changes in the 16th century also created an environment ripe for new religious forms.
The Reformed tradition was begun by Huldrych Zwingli, a contemporary of Martin Luther's, independently of Luther's reform. It was shaped decisively by John Calvin.
The Bible is the most important set of writings for Reformed and Presbyterian churches. In addition, Reformed churches share a set of important writings called creeds and confessions that set them off from other branches of Christianity.
Historical scholarship on Reformed and Presbyterian churches often reflected the theological battles of the people writing the scholarship. Recently three trends have emerged: a focus on the medieval nature of the Reformation, attention to the lives of all classes of people at the time of the Reformation, and a debate about the meaning of changes to worship space inaugurated by the Reformers.