- Coins with the legend LE III P S (Legio III Partica Severiana)
- Coins bearing the legend L III PIA may prove that the unit had received the surname Pia, 'pious.
- Coins, from Sidon, suggest that veterans of III Parthica were settled in that city.
- A Gold Coin that was found in the Roman theater of Orange, minted by the Gallic Emperor Victorinus in 271, and mentioning LEG III PARTHICA. It is of course possible that a sub unit was in the West, but it is not very likely. The reverse of this coin also has a centaur that may of been the legions emblem
According to the Notitia Dignitatum (East, 35), written at the beginning of the fifth century, the third Parthian legion was at Apadna in Osrhoene along with its sister unit the IIII Parthica, near the confluence of the rivers Chaboras and Euphrates.
The unit is unarmoured figures from Crusader Miniatures and the shields are hand painted from a description of I and II parthica shields, therefore the cross pattern and colours are hypothetical.