Immortals (Achaemenid Empire)

[2] Herodotus describes the Immortals as heavy infantry led by the Persian military commander Hydarnes the Younger; they provided the professional corps of the Achaemenid army and numbered exactly 10,000 men.

He stated that the unit's name stemmed from the fact that every dead, seriously wounded, or sick Immortal was immediately replaced with a new one, maintaining the corps as a cohesive entity with a constant strength.

Herodotus instead describes their armament as follows: wicker shields covered in leather, short spears, quivers, swords or large daggers, slings, and bows and arrows.

[4][5] The headdress worn by the Immortals is believed to have been a conical or rounded metal on top and scale or chains on the sides, resembling a ridge helmet or Phrygian cap; surviving Achaemenid coloured glazed bricks and carved reliefs represent the Immortals as wearing elaborate robes, hoop earrings, and gold jewellery, although these garments and accessories were most likely worn only for ceremonial occasions.

There is evidence from Persian sources of the existence of a permanent corps, which provided a backbone for the tribal levies (raised by satraps) who, together with increasing numbers of mercenaries, made up the bulk of the Achaemenid army.

However, recent scholarship has doubted the Roman description of the force, including their name, their size, and that they were modeled on the Achaemenid Immortals, although there may have been one or more of such distinct elite cavalry units during the Sasanian period.

[10] Under Mohammad Reza Pahlavi, the last Shah of Iran, the Imperial Iranian Army included an all-volunteer known as the Javidan Guard (Persian: گارد جاویدان, romanized: Gârd-e Jâvidân, lit.