UPI/Getty Queen Elizabeth
A regal evening meant disappointment for Queen Elizabeth's beloved dogs.
Caroline Perry, author of The Corgi and the Queen, tells PEOPLE that while researching her new picture book she discovered that the monarch's headwear sparked different reactions with her pets when she walked into their room at Buckingham Palace (yes, there was a room for the dogs!).
"When the Queen would walk into this room wearing her tiara, the dogs would slump on the floor looking really sad because they knew she was the Queen and they knew she was going to an official work function," Perry says. "When she walked in in her headscarf, they would jump up and bark and rush to the door because they knew she was off-duty Elizabeth, and she was going to take them for their walk."
Perry adds, "I love that the corgis knew: 'Oh no, not the tiara again!' "
Queen Elizabeth was extremely hands-on with her dogs, from overseeing their food menu to making them stockings at Christmas, Perry says.
"She really did adore every single one of the dogs she had as a companion," the author notes.
Tim Graham Photo Library via Getty Images Queen Elizabeth and her dogs
Perry's book documents the "love story" between Queen Elizabeth and her corgi Susan, who she received as a birthday gift when she turned 18. Susan was a constant companion for the royal during tough times, including World War II and the death of King George VI, as well as special moments like the future Queen's wedding day to Prince Philip.
Queen Elizabeth was famous for her pet corgis — in fact, Susan was the furry matriarch of 14 generations of dogs owned by the history-making monarch.
"That's how much she loved Susan," Perry, who participated in Queen Elizabeth's Platinum Jubilee Pageant in June and saw the monarch as she stepped out on Buckingham Palace's balcony, says. "She just did not want that legacy to end."
Godwin Books The Corgi and the Queen
Perry adds that the oftentimes rambunctious dogs were an expression of the Queen's own personality.
"She couldn't choose her life, but she could choose her companions," Perry tells PEOPLE. "The fact that these corgis are so spirited, so lively and so mischievous, I think in some way that was her way of expressing how she felt inside but wasn't able to convey. She was so prim and proper and never put a foot wrong, did she? Yet these naughty dogs are doing all kinds of things that maybe she wished she could do."
Lisa Sheridan/Hulton Archive/Getty Queen Elizabeth and Susan
The Corgi and the Queen by Caroline Perry with illustrations by Lydia Corry is on sale starting Nov. 22.