From WENN.com

The couple wed in a ceremony on Saturday (19May12) and the social media tycoon announced the news via an update on his Facebook.com page.

The message, which was accompanied by a photo of the newlyweds, reads, ""Mark added a life event to May 19, 2012 on his timeline: Married Priscilla Chan.""

It is understood the nuptials took place in the grounds of Zuckerberg's home in front of around 100 unsuspecting guests who were told they were attending a party to celebrate Chan's graduation from the University of California's medical school.

The couple has been together for nine years after meeting at Harvard University.

The news comes soon after Zuckerberg's Facebook.com floated on the US stock exchange on Friday (18May12) for $100 billion (£63 billion).