The ballad is inspired by his experience of working on a ship on 6 June 1944, with lyrics about men who ‘stormed the gates of hell’ and ‘died upon that blood-soaked sand’.
Profits from the song will go towards the construction of the British Normandy Memorial, which will record the names of the 22,442 men and women serving under British command who died in the Battle of Normandy.
The monument will be inaugurated on 6 June by Prime Minister Theresa May and French President, Emmanuel Macron.
On his chart success, Jim said: “I’m delighted. I never in my wildest dreams thought I would be No. 1 in any list. The more copies we sell, the more money we raise to build this memorial.
“We want people to remember all those good men. They deserve to be honoured and remembered. The thing that I remember most is seeing [the bodies of] those lads floating in the water – the ones who had to run up the beaches into the machine gun fire and never made it. I can still see their faces now.”
The following BBC report was made with Jim Radford: