Sir Paul McCartney and Heather Mills met in 1999 when the former Beatle worked on a charity single with the former model. They confirmed they were "an item" early in 2000.
Sir Paul had been largely silent about his love life following the death of his wife of 29 years, Linda, in 1998. He admitted arranging meetings about charity work to see Mills.
The couple announced their engagement in 2001, Sir Paul having proposed during a short trip to the Lake District. He admitted to having been "a bit nervous".
The wedding was a lavish, carefully shielded 300-guest affair at a castle in County Monaghan, Ireland. The couple turned down a magazine offer of £1.5m for pictures.
Sir Paul had always written poetry and painted, but it was only after meeting Mills that he found the confidence to publish and exhibit that work.
Mills has often roped in her husband's celebrity for the charity work that has earned her a Nobel Peace Prize nomination. They have campaigned together this year.
Mills has endured repeated press criticism since their wedding, including claims of a rift with Sir Paul's children. The couple have blamed "intrusion into their private lives" for their split.