However, a new book concludes the faithful animal is more likely to have been a dandie dinmont terrier, which was immensely popular in Scotland at the time – with 60 breeders in the Edinburgh area.
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The breed was developed in the Borders, whereas Skye terriers tended to be confined to the Isle of Skye, around 255 miles away.
Mike Macbeth, president of the Canadian Dandie Dinmont Terrier Club – who wrote the book with Paul Keevil, said: “There have been so many competing stories about Greyfriars Bobby that the truth has faded like the mist on an Edinburgh morning.
“But the more I researched him for our book, The Dandie Dinmont Terrier, the True Story of Scotland’s Forgotten Breed, the facts led to only one conclusion – that Greyfriars Bobby had to be a dandie dinmont terrier.”
Both authors are Crufts dog show judges and have spent the past two years researching their new book on the history and social influence of the dandie dinmont terrier.
The researchers said the early newspaper articles and sightings never suggested Bobby was a Skye terrier, but that he was almost always referred to as a “Scotch Terrier” – a term used colloquially to describe the dandie dinmont.
The story of Greyfriars Bobby is that he belonged to night-watchman John Gray, who took on the dog to keep him company through the long nights.
But Mr Gray contracted tuberculosis, and died of the disease on February 15, 1858.
Bobby refused to leave his owner’s side, and until his own death on January 14, 1872 he would stay by Mr Gray’s graveside, even in the most treacherous weather conditions.
He was commemorated with a statue near the entrance to the graveyard.
A celebration to mark 150 years since the death of Greyfriars Bobby was held in January, with a piper playing at the gravesite.