Bartholomew "Bart" Jojo Simpson is a fictional character in the FOX animate television series The Simpsons. He is voiced by Nancy Cartwright, and first appeared on the Tracy Ullman Show short "Good Night". At ten years of age, Bart is the eldest child and only son of Homer and Marge Simpson, and the elder brother of Lisa and Maggie. Bart's most prominent character traits are his mischievousness, rebelliousness, disrespect for authority and sharp wit. During the first two seasons of The Simpsons, Bart was the show's main character; while later episodes started to focus more on Homer, Bart remains one of the most enduring characters on the series, and has proven to be one of the most well-known characters in the history of American television animation.