The origin of painting dates from remote antiquity, and the art had already passed through many developments before it was applied by Gothic architects to the decoration of their buildings. "In the thirteenth century the architectonic painting of the Middle Ages reached its apogee in France. The painted windows, the vignettes of manuscripts, and the mural decorations of this period all denote a learned and finished art, and are marked by a singular harmony of tones, and a corresponding harmony with architectural forms. It is beyond question that this art was developed in the cloister, and was a direct product of Græco-Byzantine teachings."[38] [38] Viollet-le-Duc, _Dictionnaire raisonné_, vol. vii. From the archæological point of view, however, it is important to bear in mind the considerable influence exercised upon continental art by the manuscripts and miniatures of Irish monks, so early as the reign of Charlemagne. [Illustration: 116. PAINTINGS IN CAHORS CATHEDRAL. HORIZONTAL PROJECTION OF THE CUPOLA WITH FORESHORTENED FIGURES AND THEIR ARCHITECTURAL FRAMEWORK] Towards the close of the twelfth century sculpture and painting alike entered on a new phase, resulting from that process of architectural evolution we have been considering. The hieratic tradition was set aside for the direct teaching and inspiration of nature. But as the mastery of the painter increased, the mural spaces available for the application of his new methods diminished rapidly, till, by the thirteenth century, the only wall surfaces left to him were those beneath the windows, and some few triangular spaces in the vault, where the interlacing network of arches became gradually closer and closer. Finding themselves thus practically excluded from the new Gothic buildings, the painters of the day turned their attention with entire success to the decoration of ancient monuments by the new naturalistic methods. The domes of great abbey churches such as St. Front (Périgueux) offered immense bare surfaces, the concave forms of which they utilised with extraordinary skill, adorning them with compositions in which figure and ornament are so adroitly combined, that they seem to be of normal proportions, in spite of their really colossal size (Fig. 117). [Illustration: 117. PAINTING IN CAHORS CATHEDRAL. FRAGMENT OF ONE OF THE EIGHT SECTORS OF THE CUPOLA. THE PROPHET EZEKIEL] Thanks to a discovery of mural paintings made in the Cathedral of Cahors in 1890, of the greatest archæological importance, we are able to verify these statements.