In addition to the Canadians, the 21st Army Group also included the 1st Belgian Infantry Brigade, the Dutch Princess Irene Brigade, 1st Polish Armoured Division, the 1st Czechoslovak Armoured Brigade and French contingents. A legal framework for military cooperation was provided by the British Allied Forces Act 1940, and agreements were signed with the governments in exile of France and Poland in 1939 and 1940, and those of Czechoslovakia, Belgium, Norway and the Netherlands in 1941. Although these contingents were organised according to British establishments, and equipped the same as British Army units, simplifying logistics to some extent, linguistic differences remained a complicating factor.
