The illuminations of the century then are worthy of the time and also typical of the general work of the century. It is known by experts for its originality and for the wealth of invention displayed in the designs. Men did not fear that they might exhaust their inventive faculty, nor display their originality sparingly, in order that they might have enough to complete other work. As the workmen of the Cathedrals, the artist illuminators devoted their very best efforts to each piece of work that came to their hands, and the results are masterpieces of art in this as in every other department of the period. The details are beautifully wrought, showing the power of the artist to accomplish such a work and yet his designs are never overloaded, at least in the best examples of the century, with details of ornamentation that obscure and minimize the effect of the original design. This fault was to be the error of his most sophisticated successors two centuries later. Nor must it be thought the high opinion of the century is derived from the fact that only a very few examples of its illumination and bookmaking are now extant, and that these being the chosen specimens give the illumination of the century a higher place than it might otherwise have. Many examples {164} have been preserved and some of them are the most beautiful books that were made. Paris was particularly the home of this form of art in the Thirteenth Century, and indeed the school established there influenced all the modes of illumination everywhere, so much so that Dante speaks of the art with the epithet "Parisian," as if it were exclusively done there. The incentive to the development of this form of art came from St. Louis who, as we have said, was very much interested in books. His taste as exhibited in La Sainte Chapelle was such as to demand artistic excellence of high grade in this department of art, which has many more relations with the architecture of the period, and especially with the stained glass, than might possibly be thought at the present time, for most of the decoration of books partook of the character of the architectural types of the moment. Among the most precious treasures from the century are three books which belonged to St. Louis himself. One of these is the Hours or Office Book; a second, is his Psalter, which contains some extremely beautiful initials; a third, which is in the Library of the Arsenal at Paris, is sometimes known as the Prayer Book of St. Louis himself, though a better name for it would be the Prayer Book of Queen Blanche, for it was made at Louis' orders for his mother, the famous Blanche of Castile, and is a worthy testimonial of the affectionate relations which existed between mother and son.