German model Klum was still pregnant with Leni, from Flavio Briatore when she began dating musician Seal. Briatore was no longer in her life and so Seal took on the role of Leni's de facto father- he was present for her birth and Klum reportedly said that he 'was her father'. (Wikipedia)
She admitted on The Oprah Winfrey Show that she got to know Seal in a hotel in New York, after she saw him training in the gym and she said it was love at first sight.
The pair got engaged in December 2004 in a quinzee he had built on a glacier in Whistler, British Columbia and finally married on the 10th May 2005 in Mexico on the beach near Seal's home. She wore a wedding dress designed by Vera Wang.
They now have three children together; Henry, Johan and Lou and on the 21st November 2009, Klum adopted Seal's surname and became Heidi Samuel.
Seal officially adopted Leni in December 2009 and she also took his surname.
Unlike some couples who do it once, Klum and Seal renewed their vows on every one of their anniversaries in front of close family and friends. Seal said: "Each year, Heidi and I get remarried. It's a great party, but for about an hour, we go off on our own down to a private beach. We sit there with the kids and read vows to each other as the sun sets. It's a very special moment to us." (Wikipedia)
In January 2012, sadly, the couple announced that they were separating after seven years of being married. Klum filed for divroce three months later on 6th April 2012 and she arranged for her name to be restored to her birth name Heidi Klum.
Sources: IMDB and Wikipedia.