This list covers the Parthian armies from the foundation of the Parthian kingdom to the replacement of the Arcasid dynasty by the Sassanid Persians and also the vassal states of Media-Atropatene (147 BC-225 AD), Elymais (147 BC-205 AD) and Persis (141 BC-220 AD). The fully armoured cataphracts were mounted on horses whose head, neck, chest and sides were similarly protected by metal armour and the army’s strength lay in the combination of these troops with the light horse archers. The least successful Parthia armies were those using the most cataphracts and the fewest horse archers. The cataphract camels used in 217 AD were probably Hatrene. Foot were only used by the vassal states or in defending cities or in the mountains. References: Armies and Enemies of Imperial Rome P. Barker, Winter Quarters A. Duggan (novel), The Parthian V. Hurley (novel).
— Parthian Army 250 BC - 225 AD
I/43 — KIMMERIAN, SKYTHIAN & EARLY HU 750 BC - 70 AD
II/19 — SELEUCID 320 BC - 64 BC
II/22 — ARABO-ARAMAEAN 312 BC - 240 AD
II/23 — LATER PRE-ISLAMIC ARAB 312 BC - 633 AD
II/24 — EARLY RHOXOLANI SARMATIAN 310 BC - 100 AD
II/26 — SIRACAE, IAZYGES & LATER RHOXOLANI SARMATIAN 310 BC - 375 AD
II/28 — EARLY ARMENIAN & GORDYENE 300 BC - 627 AD
II/36 — GRAECO-BACTRIAN 250 BC - 130 BC & GRAECO-INDIAN 170 BC - 55 BC
II/37 — PARTHIAN 250 BC - 225 AD
II/3 — CLASSICAL INDIAN 500 BC - 545 AD
II/44 — COMMAGENE 163 BC - 17 AD & 38 AD - 72 AD
II/46 — KUSHAN 135 BC - 477 AD
II/48 — MITHRIDATIC 110 BC - 47 BC
II/49 — MARIAN ROMAN 105 BC - 25 BC
II/51 — LATE JUDAEAN 63 BC - 6 AD
II/56 — EARLY IMPERIAL ROMAN 25 BC - 197 AD
II/58 — ALAN 50 AD - 1500 AD
II/64 — MIDDLE IMPERIAL ROMAN 193 AD - 324 AD
II/69 — SASSANID PERSIAN 220 AD - 651 AD
I/43 — KIMMERIAN, SKYTHIAN & EARLY HU 750 BC - 70 AD
II/22 — ARABO-ARAMAEAN 312 BC - 240 AD
II/23 — LATER PRE-ISLAMIC ARAB 312 BC - 633 AD
II/26 — SIRACAE, IAZYGES & LATER RHOXOLANI SARMATIAN 310 BC - 375 AD
II/28 — EARLY ARMENIAN & GORDYENE 300 BC - 627 AD
II/44 — COMMAGENE 163 BC - 17 AD & 38 AD - 72 AD