King Wilhelm is a minor character in the 2002 animated film, Barbie as Rapunzel. He is the father of Rapunzel.
When Wilhelm was young man, he and Gothel are best friends. Later on, Wilhelm meeting Rapunzel's mother who arranged to marry her. Gothel was greatly offended then taking revenge for him, that she stole Princess Rapunzel, when she was a year old. King Wilhelm never court as being a violent as Gothel, he thought it was King Frederick who stole his daughter, so was began a feud.
Sixteen years after, King Wilhelm was came to his enemy's castle on the day when Stefan's birthday was celebrated. While his men tied castle's guards, and the king coming into the ballroom and deal with King Frederick. Gothel's arrival in castle, told him it was her who stole his daughter. Gothel wanted to kill King Wilhelm, but Rapunzel appeared and had broken Gothel's plans.
After Gothel was defeated by Rapunzel, Wilhelm was now that he apologized with Frederick for treating him badly during the feud, the king's friendship was restored and Rapunzel and Stefan's wedding occured, and King Wilhelm and his wife attended it and were seen applauding.