The Queen is mourning the loss of one of her last two remaining dogs just weeks before Christmas.
Loyal companion Vulcan, a dachshund-corgi cross, died a few weeks ago at Windsor, according to sources.
It is not known how old the Dorgi was, or what he died of.
But he had been the Queen's loyal pet since at least 2007, making him more than 13 years old - a good age for the breed.
Sources said the loss of her faithful companion was a blow to the 94-year-old monarch and has left her with just one remaining animal, Candy, also a Dorgi.
Her loss also comes ahead of what might be the Queen's loneliest ever Christmas.
The monarch and the Duke of Edinburgh, 99, are set to forgo the festivities spend the day 'quietly' at Windsor Castle - without forming a bubble with two other households.
The Queen is mourning the loss of one of her last two remaining dogs just weeks before Christmas. Pictured: The Queen with one of her dogs
Loyal companion Vulcan, a dachshund-corgi cross (believed to be furthest from the camera), died a few weeks ago at Windsor, according to sources
The Queen (pictured in 1952) has always looked after her own dogs as much as possible, and has a way with them that few have ever mastered
The source said: 'Her Majesty adores her dogs and it's always a blow, particularly now.'
The Queen has always been synonymous with pets, particularly her Corgis.
Her last remaining one, Willow, was put down after suffering from cancer in 2018, making it the first time the monarch had not owned a Corgi since the end of the Second World War.
Willow was the 14th generation descended from Susan, a Corgi gifted to the then Princess Elizabeth on her 18th birthday in 1944. She has owned more than 30 during her reign.
Vulcan and Candy were from a line of Dorgis introduced to the royal household when Princess Margaret's dachshund, Pipkin, was mated with one of the Queen's dogs.
The Queen brings along her dogs to meet players and officials from the New Zealand Rugby League Team, the All Golds, inside the Bow Room at Buckingham Palace on October 16, 2007
One of the monarch's loyal companions was present in Windsor Castle when the Queen greeted then-Prime Minister of New Zealand John Key in 2015
The Queen was pictured greeting a corgi - bred from her own dogs - during a visit to Northumberland in 2019
The Queen always tries to feed her dogs herself (pictured with one of her dogs), mixing their feed with a spoon and fork, from ingredients brought on a tray by a footman
It is said that if the Queen comes in wearing a tiara, her dogs lay forlornly on the carpet; if she is in a headscarf, they know it is time to go out. Pictured: One of her dogs is pictured sitting on the carpet when the Queen met members of the New Zealand Rugby League Team in 2007
They appeared alongside Willow on the front cover of Vanity Fair in 2016, shot by Annie Leibovitz to celebrate the Queen's 90th birthday.
And in March one of them was seen sitting on the Queen's lap when she moved from Buckingham Palace to Windsor to isolate during lockdown.
The Queen has always looked after her own dogs as much as possible, and has a way with them that few have ever mastered.
They live in her private apartments at Windsor and Buckingham Palace, travelling with her to Sandringham as well as Scotland on a private jet .
Pictured: One of the Queen's corgi's is seen during footage taken for a James Bond segment played during the Opening Ceremony of the London 2012 Olympic Games
She always tries to feed them herself , mixing their feed with a spoon and fork, from ingredients brought on a tray by a footman.
And even now she still likes to walk them herself.
It is said that if the Queen comes in wearing a tiara, they lay forlornly on the carpet; if she is in a headscarf, they know it is time to go out.
The Duke of York once said said his mother's love of her dogs has helped to keep her fit in old age.
'She is just amazing at her age and she walks a long way, the dogs keep her active,' Prince Andrew said.
The news of Vulcan's death comes just days after Prince William and Kate Middleton revealed their 'dear dog' Lupo (pictured with the couple and Prince George) had passed away
In 2015, however, the Queen decided to stop breeding dogs - both Corgis and Dorgis - as she didn't want to leave any behind when she dies. It has also been suggested that she was reluctant to have a large pack of pets any more, for fear of tripping over them.
Buckingham Palace declined to comment last night, saying it was a private matter.
The news of Vulcan's death comes just days after Prince William and Kate Middleton revealed their 'dear dog' Lupo had passed away.
The Duke and Duchess of Cambridge shared a picture of their beloved pup on November 22 and wrote: 'Very sadly last weekend our dear dog, Lupo, passed away. He has been at the heart of our family for the past nine years and we will miss him so much. - W & C'.
Lupo featured in many pictures with the royals, including one of the first official photos of Prince George.
The English cocker spaniel was bred from a dog which was owned by Michael and Carole Middleton, Kate's parents.
He was given to Will and Kate as a wedding present in 2011, and is believed to have helped them pick a name for Prince George.
The couple are said to have written names on various pieces of paper and scattered them on the floor.
Lupo wandered through them, but stopped when he reached the now-seven-year-old's name.
Prince William and Kate Middleton said Lupo (pictured with Prince George in 2016) was 'at the heart,' of their family since 2011
Speaking shortly after Prince George's birth in 2013, Prince William said: 'For me Catherine and now little George are my priorities, and Lupo.
'He's coping alright, as a lot of people know who've got dogs and bringing a newborn back, they take a little bit of time to adapt, but he's been alright so far, he's been slobbering around the house, so he's perfectly happy.'
The deaths of the families' beloved dogs will no-doubt make the festive season even tougher - as Covid restrictions throw the Royal's traditional Christmas Day plans into chaos.
Earlier this week, the Queen and Prince Phillip confirmed that they will not form a 'bubble' with any other family members.
The couple traditionally spend the festive season with close family at Sandringham, in Norfolk.
But this year they will forgo the festivities and remain at Windsor Castle, where they have been isolating with a 'bubble' of staff since October.
It is understood the Queen and the Duke of Edinburgh will not take advantage of the relaxed Covid restrictions to form a Christmas bubble with other households.
It means the couple face spending Christmas Day without any of their four children for the first time since 1949, when the then Princess Elizabeth left a one-year-old Charles in the UK so she could be with Prince Philip in Malta.
Prince Charles and the Duchess of Cornwall will spend Christmas at Highgrove, in Gloucestershire, although they expect to see the Queen and Prince Philip at Windsor at some point over the festive season. Camilla will also spend time with her family.
In Tier 2 regions, like Windsor, up to six people from different households are able to mix outdoors.
This means the Queen and Prince Philip could meet with family members for horse riding or walks in the grounds of Windsor Castle.
Earlier this week, the Queen and Prince Phillip (pictured together) confirmed that they will not form a 'bubble' with any other family members for Christmas
The Duke and Duchess of Cambridge are likely to spend Christmas either at Anmer Hall, in Norfolk, or at the Middleton family home in Berkshire.
Prince Edward, the Countess of Wessex and their children live at Bagshot Park, Surrey, while Princess Anne and her family live at Gatcombe Park, in Gloucestershire. Prince Andrew is the only one of the Queen's four children who lives in Windsor.
The Queen won't attend a church service on Christmas Day in order to prevent crowds gathering but is expected to worship privately in Windsor Castle's private chapel.
A Buckingham Palace spokeswoman said: 'Having considered all the appropriate advice, the Queen and the Duke of Edinburgh have decided that this year they will spend Christmas quietly in Windsor.'
The Queen and Prince Philip are currently isolating at Windsor Castle, which is located in a Tier-2 area, after leaving Norfolk for the month-long lockdown.
Prince Philip and the Queen have spent the year with a specially screened household dubbed 'HMS Bubble'.
The Queen and the Duke had a summer holiday at Balmoral in August, but spent less than half their normal 10 weeks in Scotland due to coronavirus restrictions that limited visits from family and friends.