Queen Elizabeth II, who is isolating alongside her husband Prince Philip at Windsor Castle, marked a somber occasion on Tuesday, March 30. It was on this day 19 years ago that her mother Queen Elizabeth, popularly known as the Queen Mother, died peacefully in her sleep at the age of 101 years, 238 days.

The Queen Mother, born Elizabeth Angela Marguerite Bowes-Lyon to an aristocratic family, was the longest-living royal in history and the first British-born British consort since Tudor Times. She passed away in her sleep at the Royal Lodge with her eldest daughter, the Queen, by her bedside, just seven weeks after the death of her younger daughter, Princess Margaret.

Known for her personal and public charm, the Queen Mother was one of the most popular members of the royal family. However, she wasn't originally destined to be the Queen Consort of the United Kingdom and had to unexpectedly take up the responsibility after her husband King George VI took the throne when his brother Edward VIII abdicated in order to marry American socialite Wallis Simpson.

She continued an active public life until just a few months before her death, and had some interesting experiences while doing her work. The family of long-serving Derbyshire police officer Ian Parker recently shared some fascinating anecdotes about his service in the force, including one where the Queen Mother visited his county and went missing in the middle of an official engagement, reports Royal Central.

The Queen Mother was visiting Derby in 1977, when she was 77 years old, to open the Assembly Rooms. Parker's daughter Jane Hart told the Derby Telegraph about the visit: "They lost her! There was this operation to make sure she was ok and to make sure everything went smoothly. It was a big occasion, and I remember him feeling very proud and privileged to be taking part and getting involved with it."

After a long search involving several officers, Parker found the Queen Mother in a bar having a drink. Hart said: "The Queen Mother was quite known for enjoying a tipple, and she did when she came to Derby."

Queen 90th birthday
4 August 2000: Queen Elizabeth the Queen Mother celebrates her 100th birthday from the balcony of Buckingham Palace with her daughter the Queen Ian Waldie/Getty Images