The great rose window of the south transept and the lancets below it are the gift of Pierre Mauclerc, Count of Dreux and Duke of Brittany. His arms are in the trefoils of the rose and in the central lancet. At the foot of the lancets on either side are portraits of himself, his wife, Alix de Thouars, and his son and daughter, all kneeling. From the fact that his wife died in 1226 it has been argued that the window must have been executed, or at least designed, before that date. I do not know that the argument is absolutely conclusive, but the fact seems probable. The window, however, cannot be many years older than this date. The choir would almost certainly be the first part of the church to be glazed, and the windows in the clerestory there were certainly not finished till after 1220. One, indeed, has the figure of a king of France on horseback as donor, who has always been called St. Louis. It is, however, quite possible, as far as I can see, that the figure is his father, Louis VIII., or even Philip Augustus, who died in 1223, for he bears the lilies of France only, without the castle of Castile. [Sidenote: St. Louis.] Assuming therefore that the date of the south rose is shortly before 1226, then Pierre Mauclerc, at the time he gave this and the other windows in the church which bear his arms, was practically an independent sovereign. When St. Louis ascended the throne as a boy in 1226, under the Regency of his mother, the wise and beautiful, if somewhat imperious, Blanche of Castile, Pierre Mauclerc, in company with Thibault of Champagne, who was Count of Chartres, and many other barons of France, took up arms against his sovereign, scorning to acknowledge the overlordship of a boy and a woman. Eight years later the boy and the woman, aided by the devoted support of the Commons, had brought them all to submission, and Thibault had yielded up Chartres to the Crown. It seems to me not unlikely that this latter event is marked by the gift of the north rose and the lancets below, which contain St. Louis's own arms and those of his mother. If so, the glass of Chartres may be considered as a landmark in the history of the growth of France into a nation. Whether this is so or not, the north rose cannot in any case be earlier than 1226, the year of St. Louis's accession. [Sidenote: The north rose and lancets.]