King Wilhelm is a character in Barbie as Rapunzel. He is the father of Rapunzel, and he is voiced by Christopher Gaze.For years, Frederick and Wilhelm had been at war with each other when Wilhelm thought Frederick had stolen his daughter, Rapunzel, but in truth, she had been abducted by Mother Gothel when she was a year old and hoped a fued would destroy them both due to Gothel feeling resentful of Wilhelm chosing Rapunzel's mother over her.
The two are reunited at the end of the film, where Wilhelm and Frederick forgive each other after the truth comes out from the misunderstanding.