6 June 1944 was the date set for the allied invasion of Europe, to liberate the continent from Nazi control. It was covernamed Operation Overlord but also known as D-Day, when over 150,000 British, American and Canadian forces landed on the Normandy beaches.
The words of the song were written by Sgt Harry Pynn of the Tank Rescue Section, 19 Army Fire Brigade and counters the apparent allegation by the MP Lady Astor that British troops in Europe were having an easy time. Within a short time, the song was well-known to British, Canadian and American forces, with verses being added and improvised.
The tune is Lili Marlene, music by Norbert Schultze to a 1915 poem by Hans Leip. The tune became known to the allied troops in Europe via the German loudspeakers playing the song across no man’s land.