The monarch's special day was also commemorated with a series of social media posts from her family, including a photo slideshow featured on Prince Harry and Meghan Markle's Instagram account, @SussexRoyal.
Photos included a photo of a young Queen Elizabeth, a throwback snap of the monarch with Harry and Prince William and a moment when Harry was dressed in full uniform next to his brother and was unable to keep a straight face as his grandmother inspected the line of military members. Markle also made a pair of appearances photos from her first official outing with the Queen and last year's Trooping the Colour ceremony.
"Happy Birthday Your Majesty, Ma’am, Granny. Wishing you the most wonderful day!," the caption read. "Harry & Meghan."
William and Kate Middleton also shared a tribute to the Queen on their Instagram account, @KensingtonRoyal, with the account posting a photo from a previous Trooping the Colour and writing, "Wishing a very happy 93rd birthday to Her Majesty The Queen!"
The monarch will have a second, official birthday on the second Saturday in June, which will be celebrated with the annual Trooping the Colour.
While Harry was on hand to celebrate his grandmother's birthday, Markle was absent from the festivities, as she is heavily pregnant with the couple's first child. The Duchess of Sussex is rumored to be due in late April, and her mother, Doria Ragland, recently arrived in the United Kingdom ahead of the royal baby's arrival.
"It is such a happy and exciting time for Meghan," a source told Entertainment Tonight of Markle's final days of pregnancy. "She looks absolutely radiant and is taking each day at a time. [She is] looking forward to becoming a mother."
While baby Sussex could be born any day, it's currently unclear when royal fans will get the first glimpse of the new arrival or even confirmation of the birth, as the palace recently released a statement sharing that Markle and Harry will share news of their baby with the world when they are ready.
"The Duke and Duchess of Sussex are very grateful for the goodwill they have received from people throughout the United Kingdom and around the world as they prepare to welcome their baby," the statement read. "Their Royal Highnesses have taken a personal decision to keep the plans around the arrival of their baby private. The Duke and Duchess look forward to sharing the exciting news with everyone once they have had an opportunity to celebrate privately as a new family."
Photo Credit: Getty / Chris Jackson