Nicole Richie Ties the Knot with Joel Madden

Nicole Richie married her long-time boyfriend Joel Madden at Lionel Richie's estate in Beverly Hills, but where was biological father and her former co-star Paris Hilton? INSIDE EDITION has the details.

Nicole Richie walked down the aisle with Joel Madden at Lionel Richie's estate in Beverly Hills.

The couple tied the knot after four years together and two children.

And here's the most unusual wedding guest of elephant!

Noticeably absent was Nicole Richie's former bff and co-star on The Simple Life, Paris Hilton. So where was she? Paris tweeted that she was attending a birthday party in Las Vegas. "Off to Vegas for my bff birthday!"

Also absent was Nicole Richie's biological father, Peter Escovedo. Escovedo, was a drummer in Lionel Richie's band. He gave up his daughter to Lionel Richie who adopted and raised her.

On Nicole's wedding day, we found Escovedo in San Francisco appearing with his father's band at the Hotel Nikko. He looked happy, but a world away from his daughter's wedding.

Among the stars on the guest list were singer Gwen Stefani and Khloe Kardashian.