They first spoke when Ed moved into a student house where Heidi had previously lived and messaged her asking how to work the tumble drier after spotting her name on some mail.
The pair soon started dating, and had been together for four years when they had dinner with their mothers in Wandsworth, southwest London.
Fiona Savitt soon got talking with Heidi's mother, Kay Parker, about their shared love of sailing holidays.
Kay mentioned in passing that Heidi had a "holiday boyfriend" who was also called Ed when she was 6, and said the pair had played together and held each other's hands for much of the two-week break.
Everyone thought it was a strange coincidence - Fiona even smashed her wine glass in surprise - but the conversation quickly moved onto other topics.
However, when Kay was going through her attic two weeks later, she found a dusty photo album from a sailing holiday in Gumbet, Turkey.
One of the photos, dated July 1997, showed Heidi side by side with a little boy. To Kay's amazement, she rubbed off the dust to find it was Ed, whose face was recognisable under his childhood bowl-style haircut.
"I was screaming, it was just unreal," Kay said. "Of course, I sent it to Fiona. Then loads more photographs came out.
"None of us had any idea whatsoever that Heidi and Ed had met before university. But during that two-week holiday, they held hands most of the time.
"Perhaps they just had a subconscious realisation they had shared that time together when they met as adults."
The couple were "inseparable" once they started going out and always knew they would end up getting married.
"It's crazy to think we could have got married, shared our lives together, but then never found out about this," Heidi said.
"From the moment we started dating we were inseparable and knew we were going to be together forever."
The couple married in August at Haddon Hall, a manor house in Derbyshire that dates back to the 12th century.
This was followed by a reception at grade-II listed Shiningford Farm, where hundreds of guests enjoyed a late-night dance under a tepee and a pool party the following day.
"It was just so much fun to marry my best friend surrounded by all our family and friends," Heidi said.
"It absolutely blows my mind that we could have never found out that we first knew each other all those years ago."
Fiona said: "When Kay sent me the photo of a little boy called Ed I shrieked, 'oh my goodness, that's Ed!' It was unbelievable.
"We sent it around to all our family and friends and everyone was amazed. The phones didn't stop ringing and everyone was liking it on Facebook."
Kay and Keith Parker are now good friends with Fiona and Jonathan Savitt, and regularly go on holidays with each other.
The rest of the family are also close. Ed has two sisters, Emma, and Maddy, and a brother, Matt, and Heidi has two sisters, Hannah and Olivia.
"It was not just Heidi and Ed who met on that holiday but all of us as well," Kay said. "It is just such a lovely, incredible story."
