Elizabeth and Philip organised a final get-together at Drapers' Hall.
The iconic London venue has hosted countless royal parties and was founded more than 600 years ago.
Watch the royals talk about The Queen's fabulous parties... Post continues!
Guests at the event included their daughter Princess Anne, her husband Vice Admiral Sir Tim Laurence, Princess Eugenie, the children of Prince and Princess Michael of Kent - Lady Gabriella Windsor and her brother Lord Freddie Windsor.
No doubt the Queen is excited to have some downtime. 2016 has been exceptionally busy, with her huge 90th birthday celebration taking up most of the year.
"How I will feel if people are still singing Happy Birthday to me in December remains to be seen,” she joked at her Patron’s lunch in June.
The royal couple are preparing to depart London to spend the summer in Scotland. Balmoral has a special place in the royal family’s life fabric.
Now 90, Queen Elizabeth’s earliest beloved memories are from her time in the green countryside.
“It’s the most beautiful place on earth. I think Granny is the most happy there,” Princess Eugenie once mused.