The Greek hero known for carrying out quests with his band of Argonauts is Jason. His most famous adventure involves the search for the Golden Fleece, a symbol of authority and kingship. Jason’s tale includes encounters with various mythological figures and challenges that test his bravery, leadership, and cunning. The Argonauts, a fellowship of heroes, join him in this perilous journey, showcasing themes of camaraderie and the quest for glory in Greek mythology.