アーサー・ドレイク・ブライトン,

Arthur is the eldest son and heir of the noble Brighton family. He is also Edward's elder brother. Calm and reserved, Arthur is an excellent equestrian and together with his noble steed, Alessandra, wins a competition hosted by the equestrian club in the course of the series. He and Sarah have been friends long before Lynn arrived in England. He also personifies Lynn's idea of a fairy tale prince.

(Source: Wikipedia)