The window must have been ordered at once, because Count Thibaut, "le Jeune ou le Lepreux," died himself within a year, April 22, 1218, thus giving an exact date for one of the choir windows. Probably it was one of the latest, because the earliest to be provided would have been certainly those of the central apsidal chapel. According to the rule laid down by Viollet-le-Duc, the windows in which blue strongly predominates, like the Saint Sylvester, are likely to be earlier than those with a prevailing tone of red. We must take for granted that some of these great legendary windows were in place as early as 1210, because, in October of that year, Philip Augustus attended mass here. There are some two dozen of these windows in the choir alone, each of which may well have represented a year's work in the slow processes of that day, and we can hardly suppose that the workshops of 1200 were on a scale such as to allow of more than two to have been in hand at once. Thirty or forty years later, when the Sainte Chapelle was built, the workshops must have been vastly enlarged, but with the enlargement, the glass deteriorated. Therefore, if the architecture were so far advanced in the year 1200 as to allow of beginning work on the glass, in the apse, the year 1225 is none too late to allow for its completion in the choir. Dates are stupidly annoying;--what we want is not dates but taste;-- yet we are uncomfortable without them. Except the Perche window, none of the lower ones in the choir helps at all; but the clere- story is more useful. There they run in pairs, each pair surmounted by a rose. The first pair (numbers 27 and 28) next the north transept, shows the Virgin of France, supported, according to the Abbes Bulteau and Clerval, by the arms of Bishop Reynault de Moucon, who was Bishop of Chartres at the time of the great fire in 1194 and died in 1217. The window number 28 shows two groups of peasants on pilgrimage; below, on his knees, Robert of Berou, as donor: "ROBERTUS DE BEROU: CARN. CANCELLARIUS." The Cartulary of the Cathedral contains an entry (Bulteau, i, 123): "The 26th February, 1216, died Robert de Berou, Chancellor, who has given us a window." The Cartulary mentions several previous gifts of windows by canons or other dignitaries of the Church in the year 1215.