Queen Elizabeth II turns 96 today. She is Britain’s longest serving monarch.
She actually celebrates 2 birthdays each year. Today is the actual day she was born.
Another celebration will take place in June. This is common with Royalty and it’s due to weather. Summer celebrations mean the weather will likely be better for Birthday Parade (also known as Trooping the Colour)
Today, her birthday will be noted by multiple gun salutes around London.
I would guess that someone other than the Queen will cut her birthday cake today, judging by this video from earlier this year.