Pass us the tissues - we're going to need them after this.
In a whirlwind finale spectacle, Prince William and Duchess Catherine have joined Prince Harry and Duchess Meghan in one of the last times we'll see them together as a four in an official royal capacity.
Indeed Harry and Meghan are in the thick of carrying out their final duties before they step back from their roles as senior royals for good on March 31 - and today's annual Commonwealth Day service at Westminster Abbey has proved to be the most poignant of the lot.
Even when they were full-time working members of the royal family, joint appearances from the Cambridges and the Sussexes were few and far between.
But when they did get together, there's no denying it was a spectacle to behold.
That's why it's particularly emotional to see the two brothers and their wives reunited again today, especially given it's likely the last time we'll see them attend the same formal engagement for a while.
In true fashion (no pun intended), both Meghan and Kate looked incredible in their outfits.
Meghan opted to wear a striking green cape dress, which was a bespoke design from New Zealand-born Emilia Wickstead.
The Duchess accessorised with a matching green hat by William Chambers and a small green bag by Gabriela Hearst.
Kate meanwhile wore a beautiful red coat dress by Catherine Walker.
Styling her hair in a chic up-do bun, she paired her outfit with a red Prada clutch along with her favourite red Gianvito Rossi heels.
Suffice to say these two royal women will forever remain style influencers, no matter what their status is.
William and Harry were all smiles for the event, and looked happy to be there with their wives.
The foursome worked closely together when Harry and Meghan married in 2018.
The Duchess then joined in helping to spearhead the established Heads Together charity, which was set up by Kate, William and Harry to help people suffering mental health issues.
All four royals also undertook their own engagements under the umbrella organisation known as the Royal Foundation.
In early 2019, it was revealed the two couples would then go their separate ways, with Harry and Meghan setting up their own foundation known as Sussex Royal.
Since then, the foursome have tended to do things quite separately.
Well, until today, that is.
There's no denying it is rather glorious to see them reunited again!
The poignant event in London on Monday, March 9 was also attended by several other members of the royal family, including Prince Charles, Duchess Camilla and of course Queen Elizabeth herself.
Her Majesty released a message to honour Commonwealth Day for 2020.
This year's theme was confirmed by the Palace as 'Delivering A Common Future: Connecting, Innovating, Transforming.'
Reflected in the Queen's personal message, she wrote: "Advances in technology and modern media have now enabled many more people to witness and enjoy - with remarkable immediacy - this experience of Commonwealth connection, in areas such as education, medicine and conservation."
She continued: "Looking to the future, this connectivity means we are also aware, perhaps as never before, that wherever we live, our choices and actions affect the well-being of people and communities living far away, and in very different circumstances."
WATCH: See the royals arrive at Westminster Abbey for Commonwealth Day in 2019. Story continues...
The Queen referenced sustainability in her speech, remarking that it was encouraging to see Commonwealth countries working towards making our planet more sustainable.
She ended the poignant message: "I hope that the people and countries of the Commonwealth will be inspired by all that we share, and move forward with fresh resolve to enhance the Commonwealth's influence for good in our world."