The Reformation was a period of religious and social change in Europe in the 16th century, sparked by the criticisms of the Catholic Church by figures such as Martin Luther and John Calvin. It resulted in the splintering of Christianity into various Protestant denominations, as well as political and cultural shifts in many European countries. The Reformation challenged the authority of the Catholic Church and led to new interpretations of scripture and religious practices. It also had significant impacts on the development of modern society and the formation of nation-states.