Thomas Markle was supposed to walk his daughter Meghan down the aisle on Saturday night, but there are now reports that he's pulled out of the Royal wedding.
In a statement, Kensington Palace neither confirmed nor denied that was the case.
"This is a deeply personal moment for Ms Markle in the days before her wedding," it said.
"She and Prince Harry ask again for understanding and respect to be extended to Mr Markle in this difficult situation."
So, who is Mr Markle and which other relatives of Meghan's can we expect to see at Windsor Castle?
He's where Suits star Meghan got her Hollywood pedigree
According to IMDb, Mr Markle was a director of photography for TV comedy classic Married with Children and lighting director for soap opera General Hospital.
He was nominated for a primetime Emmy for his work on the lighting for the Academy Awards in 1986.
He also won two daytime Emmys for his work on General Hospital. The first was a design award won in 1982 and the second was a lighting award in 2011.
He was also nominated for daytime Emmys on seven other occasions.
His other credits include work on The Facts of Life, Santa Barbara and a short-lived Married with Children spinoff called Top of the Heap, which also starred Matt LeBlanc before he found fame in Friends.
It was on an episode of General Hospital that Ms Markle made her television debut in 2002.
Mr Markle has retired from show business and now lives in Mexico.
According to TMZ, he won't be at the wedding because he doesn't want to embarrass his daughter or the Royal family
The backstory is that he reportedly made a deal with a photographer to stage paparazzi photos of him getting ready for the wedding.
He told TMZ that he did it to help recast his image, but that he deeply regretted the decision.
Ms Markle's half-sister Samantha Grant has taken the blame.
"The bad press over my father doing staged photos is my fault," she tweeted from a private account.
"The media was unfairly making him look bad so I suggested he do positive photos for his benefit and the benefit of the Royal family."
Meanwhile, Mr Markle told TMZ that he'd suffered a heart attack last week but left hospital early in order to attend the wedding.
Meghan's mother Doria Ragland will still be there
She too was given an important role. She'll be with Ms Markle on the morning of the wedding, with the pair due to travel to Windsor Castle together by car.
Ms Ragland is a yoga instructor based in Los Angeles. She was married to Mr Markle from 1979-1988, during which time their daughter Meghan was born in 1981.
"We are incredibly happy for Meghan and Harry," Ms Ragland and Mr Markle said in a joint statement about the engagement.
"Our daughter has always been a kind and loving person. To see her union with Harry, who shares the same qualities, is a source of great joy for us as parents.
"We wish them a lifetime of happiness and are very excited for their future together."
Ms Markle's father is white and mother African-American, and Prince Harry's office has spoken about the racism Ms Markle has experienced based on her ancestry.
"His girlfriend, Meghan Markle, has been subject to a wave of abuse and harassment," it said in a statement on November 8, 2016.
"Some of this has been very public — the smear on the front page of a national newspaper; the racial undertones of comment pieces; and the outright sexism and racism of social media trolls and web article comments."
But don't expect to see Ms Markle's half-siblings
Ms Markle has two paternal half-siblings, Ms Grant and Thomas Markle Jr.
But there have been reports of tension between them, and we're not expecting to see the half-siblings at Windsor Castle.
According to In Touch Weekly, Thomas wrote a letter to Prince Harry in April saying it's "not too late" to call off the wedding. On May 3, he reportedly followed that up with another letter saying "it's not too late to send me an invite".
Meanwhile, Ms Grant was reportedly writing a book with the working title The Diary of Princess Pushy's Sister.
She also wasn't happy about Prince Harry's comment last December that Ms Markle spent Christmas with "the family she's never had" — that is, the Royals.
"Actually she has a large family who were always there with her and for her," Ms Grant responded on Twitter.