Thus the connection between the allied arts was very close. The history of sculpture is that of architecture, for the diverse influences which marked their origin and modifications were common to both. Each reached its apogee in the brilliant manifestations of the thirteenth century, and each followed the same path to decadence less than two centuries later. Statuary and ornamental sculpture were inseparable, being executed by the same artists in pursuance of the same idea: the study of nature. In obedience to the law of increasing development they abandoned the hieratic forms imposed by religious tradition, but only to give a new expression to these very traditions, which were still preserved and venerated. Roman inspiration, and even direct imitation of Roman sculpture, is clearly traceable in the first half of the thirteenth century. Rheims, which may be accepted as the masterpiece, the last word, so to speak, of Gothic architecture, illustrates this influence in certain magnificent examples of the western porch. [Illustration: 94. RHEIMS CATHEDRAL. STATUES OF WEST FRONT. CENTRAL PORCH] [Illustration: 95. RHEIMS CATHEDRAL. STATUES OF WEST FRONT] [Illustration: 96. RHEIMS CATHEDRAL. STATUES OF WEST FRONT] The architects of the thirteenth century were pre-eminently the children of their generation. Ignoring their Latin descent they followed in the paths of the innovators so far as monumental structure was concerned; but they in their turn inaugurated a new departure by abandoning the Byzantine convention in statuary and sculptured ornament which had prevailed throughout the preceding century, in favour of the more ancient Roman tradition. In this one respect they made a salutary return upon those antique principles which they afterwards definitively abandoned. [Illustration: 97. RHEIMS CATHEDRAL. INTERIOR OF PRINCIPAL DOOR. STATUE AND ORNAMENT] [Illustration: 98. RHEIMS CATHEDRAL. INTERIOR OF PRINCIPAL DOOR. STATUE AND ORNAMENT] The influence of Roman art upon French mediæval sculpture is unquestionable. Its course may be traced through the relations existing between North and South long before the Crusades, principally by means of the great religious communities, and even more manifestly in the countless monuments raised in Gaul on Roman models, or in those constructed by Gallo-Romans for several centuries. Many of these survived the incursions of the barbarians.