The church of St Gertrude became a double collegiate church in the 9th century. The present building was constructed from 1000 in the Ottonian style: an imposing nave with two side-aisles, double transept (at the east and west ends), a huge crypt beneath the chancel, and an immense front building dating from the end of the 12th century. Parts of the front building, including the bell-tower, were restored in the 20th century after the bombardment on 14th May 1940 which also destroyed a significant part of the contents.
Building listed by RD (5-03-1936)
Listed as an exceptional heritage site of Wallonia