Bradley James: (about Arthur and Merlin's relationship) They fall out straight away when Merlin doesn't take too kindly to the way Arthur is treating a servant. Arthur tends to use brute force and ignorance to get what he wants. His privileged upbringing has an effect on his personality. When you grow up with people deferring to you it has an impact on the way you behave. But Merlin is a catalyst for a change in his behaviour. He sees in Merlin a lot more than he judges at first and it helps him realise the kind of man he could become.