From Williams

 “He introduced himself and said, ‘Hello, I’m Charlie,’ and I’m all, ‘No you’re not!’” Williams recalls, having balked at the idea of addressing the actor by his first name. “He commands such respect when he walks in a room. But I could only call him Charlie.”
http://insidetv.ew.com/2013/03/21/game-of-thrones-maisie-williams-arya-season-3


Mark lewis jones

And what was it like working alongside the likes of Peter Dinklage?

Oh it was fantastic, I mean it was a pleasure to work with Peter and Charles (Dance), and the other actors in the series It was a great experience, but it was the first series, the pilot almost, so no-one knew how popular and successful it was going to become. And Peter is a really smashing chap, very easy to work with as is Charles Dance.
http://www.thejitty.com/articles/marklewisjonesinterview