Abstract
Detailed measurements of compound piers in forty-one 12th century churches in Ile-de-France and in fifteen churches dating from the middle of the 11th century to the middle of the 12th century in Normandy indicate the following:
1) All shafts from compound piers in Ile-de-France rise entirely from the re-entrant corners of the core in the tiers of the pier. In this regard, compound piers from the transitional and early Gothic periods are homogeneous.
2) Shafts from compound piers in the main Normandy churches penetrate the re-entrant corner by up to about one half or three quarters of its volume. This feature clearly differentiates compound piers in Normandy from those in Ile-de-France.
The results prove the prototype of Gothic architecture to have been produced not in Normandy but in Ile-de-France.
