Britain’s Queen Elizabeth II celebrated her 91st birthday quietly Friday, with no formal engagements planned, Reuters reported.

Artillery gun salutes at the Tower of London and in Hyde Park marked the occasion, as the world’s oldest and longest-reigning monarch spent her birthday privately.

RELATED: We got an up-close look at The Queen’s home in Scotland, and it’s just as spectacular as you’d expect

Elizabeth was born on April 21, 1926, in Bruton Street in central London, Reuters reported. She became queen in 1952 at age 25, ascending to the throne upon the death of her father, George VI.

Despite her age, she still regularly carries out official duties. However, she has curtailed her engagements, passing them along to her son and heir, Prince Charles; and her grandsons, princes William and Harry.

RELATED: We caught a glimpse of Will and Kate’s royal backyard and it’s just as exquisite as you’d expect

Asked if she was feeling well during a trip to Northern Ireland last year, she quipped “Well, I’m still alive,” Reuters reported.

The queen has an official birthday in June which is publicly marked with a large parade of soldiers through central London, according to Reuters.

Queen Elizabeth II has aged beautifully over the years

The Irish Guards played Queen Elizabeth II “Happy Birthday” during the Changing of the Guards

Cox National Content Desk

Watch the 2017 Rare Country Awards