The Queen's three other dogs, Willow, Vulcan, and Candy, were in the portrait as well. Like Holly, Willow is also 13 and a full-blood corgi. The latter two are actually dorgis, a combination of a corgi and a dachshund.
"The most moving, important thing about this shoot is that these were all her ideas," Leibovitz told VF. "She wanted to be photographed with her grandchildren and great-grandchildren; her husband, Prince Philip, the Duke of Edinburgh; her daughter, Anne, the Princess Royal; and her corgis."
According to the Daily Mail, which was the first to report on the dog's death, insiders are saying that the Queen is "very sad" about putting Holly to sleep "but she doesn't like seeing her dogs suffer and Holly had reached a very good age."