Vachagan I "the Brave" (Վաչագան Քաջ) was the first Arsacid ruler of Caucasian Albania. Khorenatsi states that “aghu” was a nickname given to him, whom the Armenian King Vologases I (Vagharsh I) appointed as governor of northeastern provinces bordering on Armenia. He was probably the son of Vologases VI. He was followed by Vache I.