The next pair of windows, numbers 39 and 40, also removed in 1788, still offer, in their rose, the figure of a member of the Courtenay family.  Gibbon was so much attracted by the romance of the Courtenays as to make an amusing digression on the subject which does not concern us or the cathedral except so far as it tells us that the Courtenays, like so many other benefactors of Chartres Cathedral, belonged to the royal blood.  Louis-le-Gros, who died in 1137, besides his son Louis-le-Jeune, who married Eleanor of Guienne in that year, had a younger son, Pierre, whom he married to Isabel de Courtenay, and who, like Philip Hurepel, took the title of his wife.  Pierre had a son, Pierre ii, who was a cousin of Philip Augustus, and became the hero of the most lurid tragedy of the time.  Chosen Emperor of Constantinople in 1216, to succeed his brothers-in-law Henry and Baldwin, he tried to march across Illyria and Macedonia, from Durazzo opposite Brindisi, with a little army of five thousand men, and instantly disappeared forever.  The Epirotes captured him in the summer of 1217, and from that moment nothing is known of his fate.

On the whole, this catastrophe was perhaps the grimmest of all the Shakespearean tragedies of the thirteenth century; and one would like to think that the Chartres window was a memorial of this Pierre, who was a cousin of France and an emperor without empire; but M. d’Armancourt insists that the window was given in memory not of this Pierre, but of his nephew, another Pierre de Courtenay, Seigneur de Conches, who went on crusade with Saint Louis in 1249 to Egypt, and died shortly before the defeat and captivity of the King, on February 8, 1250.  His brother Raoul, Seigneur d’Illiers, who died in 1271, is said to be donor of the next window, number 40.  The date of the Courtenay windows should therefore be no earlier than the death of Saint Louis in 1270; yet one would like to know what has become of another Courtenay window left by the first Pierre’s son-in-law, Gaucher or Gaultier of Bar-sur-Seine, who seems to have been Vicomte de Chartres, and who, dying before Damietta in 1218, made a will leaving to Notre Dame de Chartres thirty silver marks, “de quibus fieri debet miles montatus super equum suum.”  Not only would this mounted knight on horseback supply an early date for these interesting figures, but would fix also the cost, for a mark contained eight ounces of silver, and was worth ten sous, or half a livre.  We shall presently see that Aucassins gave twenty sous, or a livre, for a strong ox, so that the “miles montatus super equum suum” in glass was equivalent to fifteen oxen if it were money of Paris, which is far from certain.