In Laon, placed on a ridge and overlooking the flat Picardy plain, St. Remi founded a bishopric in 487. Laon was a very important place in the kingdom of the Franks.

A Carolingian cathedral, consecrated in 800 in the presence of Charlemagne, existed here. The Carolingian structure got replaced two centuries later by a Romanesque structure, consecrated in 1071.

This cathedral was torched by the citizens during the Easter Insurrection on 25 April 1112. Bishop Waldric (aka "Gaudry"), who had served as Lord Chancellor and Lord Keeper of England, from 1103 to 1107 (and described as greedy and very violent) was killed during the uproar. The cathedral got repaired, but in the end demolished to give room for the present cathedral.

The construction began about 1160. The nave was completed after 1205. The "Cathédrale Notre-Dame de Laon", towering over the town, is a wonderful, early example of the Gothic style that developed in Northern France.

Stained glass can be found in nearly all Gothic cathedrals in France. Techniques for the production of colored glass and for the manufacturing of large windows out of it, was fast developing during the 11 th century. This was a high-tech-industry with wonderful products. Colours pour into the interior of the cathedral in the eraly monring.