The collar, worn by the romantic poet's Newfoundland, Boatswain, is inscribed with Byron's name, and shows signs of wear and damage due to the number of 'severe encounters' the dog had with the bear which formed part of Byron's menagerie.
Made of brass with a toothed edge, the collar was sold, alongside other collars, after the poet's death in 1824. It will be up for auction next month in Leyburn with a transcript of a letter from the widow of Byron's gamekeeper, detailing the first time it was sold.
Steve Stockton, of Tennants Auctioneers said: "Over the nearly twenty years that I have worked in the auction world, I have been very lucky and honoured to see and hold some incredible artefacts that represent a direct link to monumental historical events and characters.
"From the triumphant and majestic Admiral Lord Nelson’s scimitar; to the truly macabre, a handkerchief soaked in Charles I’s blood. From the brave and talismanic, a Rorke’s Drift Victoria Cross; to the heart-burstingly tragic, Captain Scott’s last letter home.
"Now I am delighted to say that I have a new object to add to the list. An object that is not only closely linked to one of the greatest poets in British history, but one that is quintessentially British in so many ways, Lord Byron’s dog’s collar."
Mr Stockton says that the Newfoundland ‘Boatswain’ was Byron’s true favourite.
When the dog tragically died in 1808 after contracting rabies, he said, his grief stricken owner erected a monument and penned the famous ‘Epitaph to a Dog’.
He also expressed the desire to be buried alongside his canine friend, though this never came to pass, as Byron famously fled abroad to escape controversy and his home was sold.
The collar will be sold with an auction catalogue from 1903 and another from 1976, giving a full and detailed lineage of ownership from the early 19th Century to the present day.
Mr Stockton continued: "Another vital factor when appraising objects is of course condition. The collar does have some signs of wear and damage, normally something that would lower value, but in this case it is an important and recorded part of the item’s history. According to the accompanying letter, the damage was done by the bear which Lord Byron kept for his own amusement. And with which Boatswain had many severe encounters."
The collar, very similar to the example held at Byron’s ancestral home Newstead Abbey, will be included in Tennants’ Autumn Fine Art Sale on November 18, with an estimate of £3,000-£5,000.
The sale also includes an impressive painting of two legendary coursing greyhounds.
The painting, by John Charlton (1849-1917), depicts the greyhounds Fullerton and Bit of Fashion who were bred and trained by Edward ‘Neddy’ Dent, the most renowned greyhound trainer of his day.
Dent, of Shortflatt Tower, Northumberland, won the Waterloo Cup – the Grand National of the greyhound coursing world – with Fullerton a record breaking four times between 1889 and 1892.
Indeed, such was his fame that Fullerton’s body was preserved, and it is now on display in the Natural History Museum in Tring, Berkshire.
This painting is a wonderful character study of dogs, and indeed the painting was exhibited in the 2003 ‘Sporting Art in Britain’ exhibition held by the British Sporting Art Trust to celebrate their 25th anniversary.
The painting is estimated at £7,000-10,000.
For further details contact Tennants Auctioneers on 01423 531661 or visit www.tennants.co.uk