Lord Ivar Mountbatten, cousin to Queen Elizabeth II, married his partner James Coyle in a 60-person wedding in Bridell Park, Devon on Saturday, September 22.
He shared photos of the wedding on Instagram, with a caption that read: "Well we did it finally! It was an amazing day despite the miserable British weather."
He went on to thank the chief Registrar who conducted the service and "set the perfect but lighthearted tone for what is a serious occasion," as well as the choir and photographer.
"Most importantly a massive thanks to my 3 gorgeous girls for being so understanding and supportive, without their support this could never have happened! And finally the biggest thank you to James for being just perfect......#wedidit #wonderfulday #despitetherain."
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He also shared a cute photo of the couple's dog, Rosie, who he said was "exhausted from participating in the marriage ceremony, not to mention hoovering up all the scraps falling from the party tables!"
Mountbatten publicly came out as gay in 2016 after gay marriage became legal in the UK in 2014.
Up until that point, only his wife Penny was aware of his sexual orientation. The couple divorced in 2011 after 17 years of marriage, but remain friends, and are parents to their three daughters Ella, Alix, and Luli.
The Daily Mail reported that Penny even walked him down the aisle at the Grade I-listed mansion venue, which was their daughters' idea.
While there were no royal witnesses, the event looked pretty lavish.
It started with a welcome dinner for 30 people on Friday night, according to the Daily Mail, and was followed by a ceremony on Saturday afternoon for an additional 30 guests.
The chapel was filled with flowers and singers from Bristol's Teachers Rock gospel choir serenaded the couple, who wore matching velvet smoking jackets.
The couple had their rings specially made by Milly Maunder designs.
The reception took place in the orangery, and involved a dinner of monkfish, speeches, and dancing, with the two best men giving toasts with flutes of Pol Roger Champagne. Instead of a cake, the couple reportedly had a "tiered collection of their favourite cheeses."
Here, Mountbatten shared a photo of the couple's tasting menus ahead of the wedding. He joked: "Jimmy's pre-wedding diet went out of the window for the day as we had 5 different starters to choose from, 2 mains and 2 puds, not to mention the selection of canapés to begin with!"
Mountbatten, the younger son of the 3rd Marquess of Milford Haven, met Glasgow-born James, an airline cabin services director, in 2014 in the Swiss alpine resort of Verbier.
While neither of them plan to change their names, according to the Daily Mail, he said: "I suppose if we had met ten years ago a civil partnership would have been nice, but now that marriage between a man and a man is legal it seems the right thing to do.
"I have had the whole marriage thing - and been very happy - but James hasn't, so I see it as a validation of my love for him."
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