Jean Errard

He introduced Italian bastions to France and was a forerunner of Vauban as well as uncle to the painter Charles Errard the Elder.

[1] Born in Bar-le-Duc to a notable family, he became a Protestant by 1572 at the latest, attending the French Reformed Church in Heidelberg, though he still served the Catholic Charles III de Lorraine.

He joined the University of Heidelberg in 1573, taking refuge in the Palatinate of the Rhine since Protestanism was banned in the duchies of Bar and Lorraine.

A good student of mathematics and geometry, he entered Charles' service in 1580 and at the start of that decade moved to Lorraine and married Barbe de Rains (or Reims), daughter of a counsellor to the chamber of accounts of Bar.

He dedicated Premier livre des instruments mathématiques (Nancy, 1584) to Charles, who had funded its publication.