The ceremony in Cannes has been Lavigne's vision since the beginning. "I've been doing it, I'm the girl, I'm the one who has the crazy vision and he's letting me be me. It's a lot and I just want to make sure I really enjoy this amazing time," she said, according to Us Magazine.
She added, "I want all the guests who come to have this once in a lifetime experience and I want everyone to say 'Wow!' and for it to be special for everyone, not just us."
The night included a song written by the couple just for the ceremony. "We'll have to release it after," Lavigne said.
The couple announced they were engaged last August. It's Chad's first marriage and Avril's second. She divorced fellow Canadian musician Deryck Whibley in 2009.