Elisabeth, of Görlitz, Duchess of Luxembourg 1390 - 1451 read more on Who is Who...
On her way to find Arnaud de Montsalvy and convince him that he was falling for an imposter, a false Jeanne d'Arc - she traveled to the Duchy of Luxembourg. Elisabeth of Görlitz did not want to believe Catherine at first.
But Catherine was able to prove very simple, that the Duchess had been hoodwinked by Claude/Jeanne, who had a  uncanny likeness to the real Jeanne d'Arc, who had been burned at Rouen years ago.

Marie Laurence  played Duchess Elisabeth of Luxembourg in in the TV-Adaption Catherine, Il suffit d'un amour

non fictive character
Elisabeth was the only daughter and heiress of John of Görlitz, the third son of Emperor Charles IV. He was Duke of Lusatia and Görlitz, and also Elector of Brandenburg for a brief period. Her mother, Richardis of Mecklenburg-Schewerin, was the daughter of King Albert of Sweden.The Duchy of Luxembourg was mortgaged to Elisabeth by her uncle, Sigismund, Holy Roman Emperor. He was unable to repay the loan, and subsequently left Elisabeth in control of the duchy.Her first marriage took place in Brussels on 16 July 1409, to Antoine, Duke of Brabant. He defended her against three uprisings of the Luxembourg nobility, until his death in 1415. They had two children. John of Bavaria was her second husband. He died in 1425, and they did not have any children. After his death, she became heavily indebted.
In 1441, she made a treaty with Philip III, Duke of Burgundy, allowing him to immediately assume the administrative duties of Luxembourg and inherit the duchy upon her death. He agreed to this, but chose to launch a night attack on the territory two years later, taking immediate control. Elisabeth was subsequently expelled from Luxembourg by Philip's forces.

Escorneboeuf, soldier from Gascogne
Sergeant Escorneboeuf, (sent by Jean de Xaintrailles), leader of about nine men, to protect Catherine and Arnaud, to have a save return to Montsalvy, when they were still in dishonor with Charles VII). Brutal type of man, killed men for no apparent reason. Arnaud de Montsalvy sent him packing, catching him looking through a keywhole, while Catherine suckled little Michel.
Came one day to Carlat, Arnaud could not refuse to take him into service again, since Comte Bernard d'Armagnac spoke up for him (he was in the service of Cadet Bernard) tried to kill Catherine on Marie de Comborn orders.


there is no Escorneboeuf in the tv-series