Cardinal Désiré-Joseph Mercier, Archbishop of Malines, was the incarnation of the Belgian resistance against the German occupation during the First World War. With his famous pastoral letter of Christmas 1914 ‘Patriotisme et Endurance’ he reached a wide audience, and gained international influence and respect.

Mercier’s distinct patriotic stance clearly determined his views of national politics, especially of the 'Flemish question', and his conflict with the German occupier made him a...