Who wrote the children's story "The Old Man of Lochnagar"?

"The Old Man of Lochnagar" is a children's book written by Charles, Prince of Wales, and illustrated by Sir Hugh Casson. The story revolves around an old man who lives in a cave in the cliffs surrounding the corrie loch under the Lochnagar, a mountain which overlooks the royal estate at Balmoral in Scotland where the Royal Family spend much of their summer holidays.

The story of the old man of Lochnagar was one Prince Charles had told some years earlier to entertain his brothers, Andrew and Edward, when they were young. The book was published in 1980 in aid of "The Prince's Trust" charity.

The book was later made into an animated short film by the BBC, with Robbie Coltrane providing the voice of the hermit and Prince Charles narrating. The film was titled "The Old Man of Lochnagar" in the UK and "The Legend of Lochnagar" in North America. The book was also adapted into a musical stage play. In 1984, Prince Charles read the story on the BBC children's programme 'Jackanory'. He has also read it in Welsh and Scottish Gaelic translations on television.