A day after Facebook went public, its co-founder and CEO Mark Zuckerberg Saturday updated his relationship status to married.  Zuckerberg had an eventful timeline this week with the addition of two events - Facebook IPO Friday and his wedding with his longtime girl friend Saturday.

Zuckerberg (28) tied the knot with his girlfriend Priscilla Chan (27) in a simple ceremony held in their backyard Saturday. The multi-billionaire placed a simple ruby sparkler in Chan's finger in the ceremony which was attended by less than 100 guests in Palo Alto, California.

The wedding came as a surprise to the guests as they thought they were attending a party to celebrate Chan's graduation from the UCSF medical school. The guests were informed about the marriage after they arrived at the event.

Both Zuckerberg and Chan announced their wedding on Facebook by changing their relationship status and by adding a Life Event to their Facebook timeline along with their photo in wedding dresses. Zuckerberg wore a dark blue suit and tie with a white shirt while Chan was dressed up in a traditional white laced wedding dress with a veil.

The event and the status were being liked by thousands of people and hundreds were commenting their wishes to the couple in their timeline.

Zuckerberg met Chan in Harvard in 2003 before he co-founded Facebook in 2004 and they had been dating for the last nine years.

Chan, born in Braintree in Massachusetts, did her schooling at Quincy High School and worked at FASE as director/mentor before completing her graduation from Harvard in 2007, according to her Facebook profile. For a year, she worked as a teacher at the Harker School and later joined the UCSF for her medical education.

Chan has written in her profile that she likes cooking, the food network, warm places, sun dried tomatoes and diet a&w. i am a simple creature.

Check out the pictures of the couple below: