In this expedition Pollux slew Amycus, son of Neptune, and king of Bebrycia, who had challenged all the Argonauts to box with him. This victory, and that which he gained afterwards at the Olympic games which Hercules celebrated in Elis, caused him to be considered the hero and patron of wrestlers, while his brother Castor distinguished himself in the race, and in the management of horses.
Cicero relates a wonderful judgment which happened to one Scopas, who had spoken disrespectfully of these divinities: he was crushed to death by the fall of a chamber, whilst Simonides, who was in the same room, was rescued from the danger, being called out a little before, by two persons unknown, supposed to be Castor and Pollux.
The Greek and Roman histories are full of the miraculous appearance of these brethren; particularly we are told they were seen fighting upon two white horses, at the head of the Roman army, in the battle between the Romans and Latins, near the lake Regillus, and brought the news of the decisive victory of Paulus Aemilius to Rome, the very day it was obtained.
Frequent representations of these deities occur on ancient monuments, and particularly on consular medals. They are exhibited together, each having a helmet, out of which issues a flame, and each a pike in one hand, and in the other a horse held by the bridle: sometimes they are represented as two beautiful youths, completely armed, and riding on white horses, with stars over their helmets.