From Inscriptions we also know that the Legio was at one time in Lycia and Cyrenaica. The First Parthian were all but destroyed in the siege of Singara in 360AD, sub units retired to Bezbade (modern Cizre, Turkey) but this also fell to the Sassanids. Some must of escaped these disasters and the Legion was reformed and transferred to Constantina (Tella, on the road between Edessa and Nisibis) and later Cepha where they remained until the 5th century.
Gordian III & Tranquillina. 238-244 AD. Æ 33mm (26.18 gm). Singara mint.Laureate, draped and cuirassed bust of Gordian, right, facing diademed and draped bust of Tranquillina left Tyche seated left on rock, holding small branch over river god swimming left; above Centaur Sagittarius shooting arrow from bow.The units emblem was a Centaur, the figures are from the crusader range, the shields are hand painted and are copied from a tile mosaic which is attributed to a Parthian Legio.