John Calvin (French: Jean Calvin or Jehan Cauvin; 10 July 1509 – 27 May 1564) was an influential French theologian and pastor during the Protestant Reformation. He was a principal figure in the development of a systematic exposition of Christian theology. His “Institutes of the Christian Religion” are so definitive that those who hold to this systematic exposition of the scriptures have come to be called Calvinists and the exposition itself has come to be called Calvinism.
Originally trained as a humanist lawyer, he broke from the Roman Catholic Church around 1530. After religious tensions provoked a violent uprising against Protestants in France, Calvin fled to Basel, Switzerland, where he published the first edition of his seminal work The Institutes of the Christian Religion in 1536.