The Sassanian immortals

The Sassanian Persians are generally regarded as having maintained an elite cavalry unit called the 'Immortals', the formation of which was inspired by Achaemenian practice, thereby demonstrating continuity between the two dynasties, as per the general scholarly view. This article assembles all the pertinent evidential material from the Greco-Roman sources in order to present a comprehensive critique of this position. It emerges that references to Sassanian Immortals in sources emanating from the Mediterranean world may owe more to classicizing fancy than to historical reality, and particularly a desire to approximate late-antique wars against Persia with those waged by the West against Achaemenian kings.