Ombudsman institutions, in their many guises, have now been around for two centuries. However, it is only since the Second World War that these institutions have been more widely embraced as an important component of democratic governance. This trend has been reflected in the gradual proliferation of ombudsman institutions over the past fifty years. This policy paper is part of an ongoing research project which will analyse the functions and performance of ombudsman institutions in relation to the armed forces and identify lessons of best practice on the basis of comparative research.