When describing the mighty armies of the Persian empire, the ancient Greek historian Herodotus paid particular attention to the battalion of elite troops he dubbed the "Immortals" — a unit that seemed to the Greek scribe to always be at its full complement of 10,000 soldiers. The Persian army of the time was a vast, multiethnic force, but the Immortals were all from the empire's central Persian provinces. Garbed in colorful raiment that concealed their scale armor, the Immortals were adept with both bow and blade and were honored so highly that they were permitted to travel with their own exclusive retinue of cooks and concubines. Thousands of years later, the Shah of Iran invoked the legacy of the country's mighty past and named his elite household guard the Javidan — or Immortal — guard. Those Immortals, though, couldn't withstand of the Islamic revolution.