Duncan Campbell was an Scots nobleman who died on July 18, 1758, as a result of wounds received in a frontal attack against French forces at Fort Carillon (Fort Ticonderoga). The legend associated with Campbell is that three years previously, Campbell gave shelter to a stranger who turned out to have killed Duncan's brother. Faced with the conflict between betraying a guest or taking vengeance for the death of his brother, Campbell compromised by allowing the killer to hide out in a cave. The ghost of Campbell's brother is claimed to have appeared to Campbell in a dream and promised to meet him again at "Ticonderoga" a place that he surely had never heard of.

Campbell's regiment of Highlanders took many casualties in the ill-fated attack on Fort Carillon. Legend has it that the battle was replicated in the clouds over Inverawe in Scotland on the afternoon of the attack. The story of the ghostly prediction and the apparition in the clouds over Inverawe has been repeated a number of times in magazines, song, and used several times in television scripts.

There are two prominent British journalists called Duncan Campbell. One is a freelance investigative journalist and television producer who has specialised in intelligence issues, was prosecuted under the Official Secrets Act in the "ABC Trial" in 1978 and made the controversial series Secret Society for the BBC in 1987 (see Zircon affair). The other is a long-standing correspondent of The Guardian who has written on crime and Latin America.