From Dinklage

Award-winning actor Peter Dinklage (Tyrion Lannister) revealed he loves working with Charles Dance, who plays Lord Tywin Lannister.
"I love the man, he's a legend. I grew up watching him and I've always loved his work. He's perfect for that role and we have such a good time off set," he said.
http://www.independent.ie/woman/celeb-news/harington-i-could-do-fight-scenes-29141205.html