Reformed churches

The Reformed churches are a group of Christian Protestant denominations that are historically related by a doctrine that is identical or similar to Calvinism. It developed in the Swiss Reformation led by Huldrych Zwingli and John Calvin, but soon afterwards appeared in nations throughout Western Europe. Each nation in which the Reformed movement was originally established had its own church government. Several of these local churches have expanded to worldwide denominations and most have experienced schisms into multiple denominations. 
History.
The first Reformed Churches were established in Europe in the 1500s, in the wake of the Protestant Reformation.
Form of doctrine.
Reformed doctrine is expressed in various texts]. Some of them are used by many denominations. Different denominations use different confessions, usually based on historical reasons. Some of the confessions still commonly in use are (with year of writing):
Form of governance.
Reformed churches have two main forms of ecclesiastical polity: