Viollet-le-Duc was the first architect since the Middle Ages to reach a profound understanding of the principles of Gothic construction and he devoted his careful scrutiny to the structure of Notre-Dame. The tall, monolithic and incredibly thin colonettes which support the apse vaults he describes as "splender pins, as strongs as if they were of cast iron, thanks to the quality of the stone employed".
The building dates from the second quarter of the thirteenth century. A rather unusual anecdote related by the Dominican Etienne de Bourbon gives the date of 1240 for near completion. A certain usurer of Dijon, walking beneath the west façade, was killed by the fall of one of the gargoyles. The other usurers of the city clubbed together and obtained the removal of all these dangerous objects, of which the Dominican was an eye-witness. The present gargoyles were placed in the façade only in 1881. They are none of them gargoyles in the proper sense of the word, for they play no part in the water drainage system. They form the most striking and original feature of the church, for the west front takes the unusual form of a vast screen of masonry.