After the Second World War , in light of the mass murder of Belgian Jews during The Holocaust , the anti-semitic elements of the cult were de-emphasised . In 1968 , in the wake of '' Nostra aetate '' issued by the Second Vatican Council , the Archdiocese of Mechelen-Brussels officially derecognised the cult . In 1977 Cardinal Leo Joseph Suenens installed a plaque in the cathedral to highlight this . On November 16 , 2006 at the inauguration of the exhibit '' Menorah in the Cathedral '' by Jean Paul Leon presented by the Jewish Museum of Belgium , Monsignor De Kesel addressed the attendees and Albert Guigui as Chief Rabbi of the Great Synagogue of Europe and apologised for the commemoration of the Brussels massacre on the windows of the Cathedral . The former chapel of Saint Gudula is now the cathedral museum , displaying its treasures , including the former reliquaries , with contextual information
The Holocaust
The Holocaust
Brussels massacre