 Calvin sheltered Marian exiles ( those who fled the reign of Catholic Mary Tudor in England ) in Geneva starting in 1555 . Under the city 's protection , they were able to form their own reformed church under John Knox and William Whittingham and eventually carried Calvin 's ideas on doctrine and polity back to England and Scotland . However , Calvin was most interested in reforming his homeland , France . He supported the building of churches by distributing literature and sending ministers . Between 1555 and 1562 , more than 100 ministers were sent to France . These efforts were funded by the church in Geneva , as the city council had refused to become involved in missionary activities at the time . Henry II severely persecuted Protestants under the Edict of Chateaubriand and when the French authorities complained about the missionary activities , Geneva was able to disclaim responsibility . 
