A three horse chariot ridden by goddess has been a rare sight on the Roman architecture. In ancient Greece, this chariot might be used for war, but in terms of racing its reference was never found. Yet, the popular chariot of Arcilles and lliad was drawn by two immortals and one mortal horse.
The driver of a trig was called Trigarius, since the yoking of three horse chariots was uncommon. The Etruscan racing used the third horse as a trace-horse on the turns. The Isidore of Seville portrayed Triga has infernal gods and the three horses represent the three ages of human being childhood, youth and old age.
Roman rarely race three horse chariots, during Emperor August reign Dionysius mentioned triage racing. The first-time Triga appeared on Roman coinage around First Punic War with goddess Victory driving it. The denarius of Roman Republic issued in 111-110 BC depicted Victory driving Triga on the reverse side, it also illustrates the initials of the three moneyers Appius Claudius, T. Manlius (Malloleius or Mallius) and Q. Urbinius in the exergue.
To know more about Roman coinage click here.