The portal War Museums in Europe is a Dutch website with the simple aim of putting concise information about European war museums conveniently together. The website offers a alphabetically ordered list, a country list and a rating index. The website mentions 136 museums. Clearly these are not all museums covering only the First World War, and it seems this small portal has not been recently updated. The website can be viewed only in English.
The International Council of Museums (ICOM) has an International Committee of Museums and Collections of Arms and Military History (ICOMAM) in which most of the large and national war museums and military museums in Europe participate.