This is the oldest church in Paris, begun in 542 when Childebert I founded the Benedictine Abbey of Saint-Germain-des-Pres. The site was attacked by the Normans and the church was rebuilt in 1014 and rededicated in 1163. Its west end tower was pierced by a portal, completed in the twelfth century, which collapsed in 1604 and was replaced in 1606 by the present classicising portal, by Marcel Le Roy. Its choir, with an apsidal east end, provides an early example of flying buttresses. The Abbey buildings were all destroyed in 1794 except for the abbey church, now know simply as Saint-Germain-des-Pres. The tomb of philosopher Rene Descartes is located in one of the church's side chapels.