There is, therefore, some doubt as to what exactly cataphracts were in late antiquity, and whether or not they were distinct from . Some historians theorise that cataphracts and were one and the same type of cavalry, designated differently simply as a result of their divided geographical locations and local linguistic preferences. Cataphract-like cavalry under the command of the Western Roman Empire, where Latin was the official tongue, always bore the Latinized variant of the original Greek name, . The cataphract-like cavalry stationed in the Eastern Roman Empire had no exclusive term ascribed to them, with both the Latin variant and the Greek innovation being used in historical sources, largely because of the Byzantines' heavy Greek influence (especially after the 7th century, when Latin ceased to be the official language). Contemporary sources, however, sometimes imply that were in fact a heavier type of cavalryman, or formed special-purpose units (such as the late , a Roman equivalent of horse archers, first mentioned in the ""). Given that "cataphract" was used for more than a millennium by various cultures, it appears that different types of fully armored cavalry in the armies of different nations were assigned this name by Greek and Roman scholars not familiar with the native terms for such cavalry.