Prince Charles is celebrating his 70th birthday this year and it's going to be a celebration to remember.
Now that the countdown is on for the festivities, it's been confirmed that two of our other favourite royals will be there too. In a post on the official Danish Royal Family website, it's been confirmed that Crown Princess Mary and Crown Prince Frederik will be in attendance.
Mary and Frederik invited Charles and Duchess Camilla to visit Denmark as part of their Diamond Jubilee tour of Scandinavia in 2012, so it's no surprise the younger couple has scored an invitation. The Danish royals also have a good relationship with Prince William and Duchess Catherine so they'll be able to share a champagne with a few friendly faces.
The Duke and Duchess of Cambridge first met Crown Princess Mary and Crown Prince Frederik shortly after their 2011 wedding, and it's safe to say that Mary and Catherine have a few things in common.
To mark Prince Charles' milestone birthday, the Queen will host a reception and dinner in the State Rooms of Buckingham Palace on November 14. Not only will close family members be there, but several other European royal dignitaries will be flying in.
Queen Elizabeth certainly knows how to throw a party as well. For her 92nd birthday at the Royal Albert Hall this year, the royal celebrated with her family and enjoyed performances from Kylie Minogue, Sir Tom Jones and Craig David.
However, while there may be a wild party later, we imagine this reception will be a slightly more formal occasion.
WATCH: Kylie Minogue performs at the Queen's 92nd birthday. Post continues...
And when a state banquet is involved, that means it's time to dip into the royal jewellery box.
While Duchess Catherine has had some dazzling moments wearing royal jewels, most recently the Cambridge Lover's Knot tiara, this is the first time we may see Duchess Meghan sport a tiara since her wedding day.
This is because royal etiquette dictates that tiaras are only worn for weddings, state banquets or official receptions, and despite attending numerous events since she became a royal, this will be the Duchess of Sussex's first white tie event.
"The first time a tiara is worn is by the bride on her wedding day. It signals the crowning of love and the loss of innocence to marriage. The family tiara is worn by the bride and from that moment onwards it was the groom's jewellery she was expected to wear. It was a subliminal message that she had moved from her family to another," Geoffrey Mun explains in his book Tiaras - A History of Splendour.
"Nowadays few adhere to this protocol, even if they are aware of it."