Hercules fell in love with Deianeira, a beautiful princess who rode her chariot and participated in military exercises. He was a famous hero, but Achelous was a river-god. He challenged Hercules into a wrestling contest for the hand of Deianeira. Achelous assumed the shape of a large fish that terminated in the bust of a man, while still retaining the horn and ear of a bull. Hercules pressed the throat of the Achelous with his left arm, while his right arm bore down on the horn in order to bend Achelous to the earth. Eventually, the horn broke and Hercules won the hand of Deianeira. Achelous implored Hercules to return the horn to him in exchange for the Horn of Plenty. Hercules agreed and donated the Horn of Plenty to the Aetolians.