While illumination was not an invention of the Thirteenth Century, as indeed were very few of the great art features of the century, during this time book decoration was carried to great perfection and reached that development which artists of the next century were to improve on in certain extrinsic features, though the intrinsic qualities were to remain those which had been determined as the essential characteristics of this branch of art in the earlier time. The Thirteenth Century, for instance, saw the introduction of the miniature as a principal feature and also the drawing out of initials in such a way as to make an illuminated border for the whole side of the page. After the development thus given to the art in the Thirteenth Century further evolution could only come in certain less important details. In this the Thirteenth Century generations were accomplishing what they had done in practically everything else that they touched, laying foundations broad and deep and giving the superstructure the commanding form which future generations were only able to modify to slight degree and not always with absolute good grace.
Humphreys in his magnificent volume on The Illuminated Books of the Middle Ages, which according to its title contains an account of the development and progress of the art of illumination as a distinct branch of pictorial ornamentation from the Fourth to the Seventeenth centuries, [Footnote 17] has some very striking words of praise for Thirteenth Century illuminations and the artists who made them. He says:
[Footnote 17: The Illuminated Books of the Middle Ages, by Henry Noel Humphreys Longman. Green, Brown and Longmans, London, 1848.]
"Different epochs of the art of illumination present widely different and distinct styles; the most showy and the best known, though the least pure and inventive in design, being that of the middle and end of the Fifteenth Century; whilst the period perhaps the least generally known, that of the Thirteenth Century, may be considered as the most interesting and original, many of the best works of that period displaying an astonishing variety and profusion of invention. The manuscript, of which two pages form the opposite plate, may be ranked among the most elaborate and profusely ornamented of the fine books of that era; every page being sufficient to make the fortune of the modern decorator by the quaint and unexpected novelties of inventions which it displays at every turn of its intricate design."