Queen Elizabeth II Celebrates 91st Birthday With London Salute

LONDON (CBSNewYork) -- Today, Queen Elizabeth turns 91 years old, and while it's a big birthday, you won't see the big celebrations until June when she marks her "official birthday."

PHOTOS: Queen Elizabeth II's 91st Birthday Celebrated In London

As far as her actual birthday, she likes to keep it pretty low-key.

Of course for Royalty, low key celebrations include firing cannons.

We saw the Queen in bright green, leaving Easter Mass last Sunday, but today, she's probably out riding her horses in Windsor Great Park, CBS Royal Commentator Victoria Arbiter reported.

"She loves to be out and about with the dogs -- all her favorite things," Arbiter said.

PHOTOS: Queen Elizabeth II Through The Years

To mark the Queens Birthday, Buckingham Palace shared a christening photo of the future monarch from 1926, and the royal family shared a 1952 photo of Queen Elizabeth and Prince Charles.

Last year, when the Queen turned 90, the country celebrated all year. But this year, Britain's longest-reigning monarch will mark her "official birthday" on June 17th with a parade in London known as the "Trooping the Colour" ceremony -- a tradition from 1748, where the public can take part in honoring their King or Queen.

"The queen is so remarkable, she's still incredibly fit, agile, energetic," Arbiter said.

Some took to Twitter to pay tribute to the Queen.

"Very Happy Birthday, Your Majesty -- you are an inspiration to us all," former British prime minister David Cameron tweeted.

If you'd like to send the queen a personal birthday message, just use the hashtag #HappyBirthdayHerMajesty.

The Queen Elizabeth II Garden at Hanover Square in Manhattan will honor the Queen on England Day on Saturday.

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