Eduardo Saverin was a senior at Harvard University when he met Mark at a 'punch' party. While there were already a large number of students working on similar types of social networking sites, it was the combination of Mark's creativity and Eduardo's business accumen that made the project successful. When he was later forced out of the business, Saverin sued Zukerburg and won back his designation as the co-founder of Facebook.
The Accidental Billionaires: The Founding of Facebook: A Tale of Sex, Money, Genius and Betrayal