In fact, I am deeply convinced that the most probable candidate is Guigues IV, Count of Forez (Comte de Forez):
(there are two numbering schemes for the Forez Counts with the most exact name being Guigues V, 4th Count de Forez - he is referred both as Guigues IV or Guigues V)
For:
- His name is a perfect match, pronounced [kɔ̃t-də-fɔʁɛ] is as close as you can get to 'Kondofrej'
- He left for Jerusalem with the Baron's Crusade in 1239. Then at some point, a group of knights were called by Pope Gregory to defend the Latin Empire and headed for Constantinople. They were able to negotiate an agreement with Ivan-Asen II of Bulgaria to let them pass and reached Constantinople in 1240 without fighting
- The group that headed to Constantinople was led by Baldwin II, also known as Baldwin of Courtenay, the last Latin Emperor
- The official death record of Guigues IV is from October 29 1241, but "Histoire des Ducs de Bourgogne" says that this is but the date of his death certificate and testament were in fact written by his son afterdelivered once it became clear that he had died during the Crusade on his way back - his death is first mentioned as early as February 1241 - and his son did not receive his title until 1242 exactly because the circumstances surrounding his death were not clear
- He died from illness, which is consistent with the local legend
- His son, Guigues V, also took part in a later Crusade - and it seems that the death of his father did play a major role in this decision
Still unclear:
- Was Guigues IV part of the group that crossed Bulgaria and met Ivan-Asen II?
- Who and how brought Guigues's sarcophagus back to the church he had built in Montbrison
Against:
- At least one source places Guigues IV at Ashkelon in 1240
(French) Histoire des Ducs de Bourbon et des Comtes de Forez, Jean-Marie de la Mure, 1809, printed version of a 1675 manuscript, chapters XXII and XXIII, Guigues IV is referred as Guy IV
(English) The Barons' Crusade: A Call to Arms and Its Consequences, Michael Lower, 2005
(French) Annuaire historique pour l'année 1856 A simple list of birthdates, dates of death, marriages and issue for a large number of French medieval lords - here he is referred as Guigues V and his son as Guigues VI - with the same date of death - October 29 1241
(English) The Crusading Counts of Nevers, Elizabeth Siberry, 1990 mentions him in Ashkelon in 1240
(French) Chronique de Notre-Dame-d'Espérance de Monbrison - 1212 - 1847, Abbé Renon, 1847 contains a detailed chronicle of his life that goes to 1239 - when he left on the Crusade - there is nothing about the sarcophagus
