As reformed theology, also known as Calvinism, continues to gain renewed interest it’s important to look at the historical leaders and events that led to its development. Although the reformed faith is typically associated with churches calling themselves “reformed”, actually all Protestant churches are reformed in the sense that they have their roots in the Protestant Reformation that occurred more than five centuries ago. This article (almost 6,500 words) not only chronicles the leaders and history of the movement and outlines the basic tenants as found in the Calvinistic T.U.L.I.P concept of what it means to be reformed, but also shows how it differs from Arminianism, which is the other main type of Protestant theology.