Who is Jean de Coras, Jean Coras, Judge Coras from The Return of Martin Guerre and what is their importance?

Jean de Coras is one of the judges at the court in Toulouse, in the second trial, the appeal, of Arnaud du Tilh, alias Martin Guerre. At the same time he is becoming a Protestant, and the author probes what influence these sympathies could have had on the trial. He is later lynched by a mob.