The air campaign included 5 squadrons from New Zealand, 7 from Australia, 14 from Poland, 6 from France, 3 from Czechoslovakia, plus 2 each from Belgium, the Netherlands and Norway.
Meanwhile a fifth of the German 7th Army were Osttruppen (Poles by birth in the main.) On D-Day itself the US 4th Division fought a bizarre battle with a German cavalry unit consisting of former Red Army prisoners.
Captured Red Army hiwis in German uniform were sent back to the Soviet Union, where many were executed, but the majority were dispatched to slave labour camps.
Roughly 1m of them served under Wehrmacht command under varying degrees of duress. Americans coming across Soviet troops with central Asian or Mongolian features often mistook them for Japanese.
3 Troop of 6 Commando (Sword) included Belgians, Dutch, Norwegians and Poles. Meanwhile X Troop consisted almost entirely of German Jewish refugees. They had been issued with English names and issued with identity discs marking their religion as C of E in case they were captured. (Some RAF pilots reportedly also wore the khaki uniforms of the infantrymen they referred to as 'brown jobs' in order to avoid being shot when captured.)
On June 7 some French civilians near Saint-Marcouf found with German weapons were executed on the spot by Allied soldiers unable to conceive that they might have been accumulating these weapons in order to hand them over to the Resistance.
"Many had never been to another country where a foreign language was spoken and found it hard to see a difference between 'enemy-occupied' and just 'enemy'," Beevor notes. Plus ça change, plus c'est la même chose, as the locals might say.
The greatest achievement of the Resistance was to delay the deployment of the Das Reich Division to Normandy: it took 17 days in all, 14 more than anticipated. SS reprisals were severe. At Oradour-sur-Glane 642 people were massacred.