So, can anyone guess what John Calvin and Guy de Bres had in common? I mean, besides the fact that they were Reformed? While both spoke French, their native tongue was likely Picard. Noyon was the birthplace of Calvin — Noyon is in Picardy, France. Picard was also spoken in Mons, the town in present-day Belgium where de Bres was born. Picard was also the lingua franca of the cities where de Bres served as a pastor: Lille, Tournai and Valenciennes.