Telegrams tell of first attack by Nazi Germany on Britain when U-Boat sank passenger ship
The Athenia carrying 1,103 passengers was attacked in September 3rd 1939 when the German captain mistook her for an armed merchant ship.
Her sinking led to the deaths of 118 people including a Canadian child which brought the Commonwealth country into the conflict.
The captain of the submarine had attacked the Athenia after mistaking it for an armed merchant ship.
When Adolf Hitler found out he was furious and made the trigger-happy captain re-write his log so stop news of the sinking from getting out.
The three telegrams were kept by Capt McCelland and were handed down through his family.
They are now about to go on public show for the first time at London's Imperial War Museum after his grandson Greg McCelland, 50, re-discovered them in a drawer.