Quote Originally Posted by MeinPanzer
The hetairoi were, until Magnesia, generic greek middle-heavy cavalry. If they weren't, then what would you suggest they were, and what evidence do you have to support it?
And here I thought the hetairoi were the Macedonian elite heavies... originally. It seems sensible enough that later Successor elite squadrons drawn from the nobility would keep using the prestigious name, although I would imagine the the Philippo-Alexandric "page" system had to go already on practical grounds. Doesn't mean they were the only shock cavalry around or the only ones who fought with the xyston though. The long lance was much too useful a weapon for there to not be non-hetairoi users, and the somewhat lighter and more all-purpose hippeis pattern apparently existed alongside the specialized lancers.

Hetairoi, being wealthy, probably provided their own armament. Thus, these soldiers probably brought along their armament to fight, whether it was in the east or west. There's no reason to think that they had separate armaments for fighting on the eastern frontier than they did in the west.
But hetairoi dwelling in the east would probably tend to have a little different taste for details of equipement than ones whose estates lay in, say, Asia Minor, no ? Anyway, they might also have possessed several different weapon complements for different campaign purposes - didn't you yourself mention Companions sometimes using javelins earlier ?

It's very clear that the king's friends were drawn from all portions of the empire, and the largest concentration of population was in Asia Minor. Therefore, a larger proportion of the hetairoi were probably drawn from Asia Minor, and a large proportion probably did campaign in the east. Livy says that the hetairoi at Magnesia were mostly Syrians with Lydians and Phrygians.
...weren't the Seleucids' more eastern holding by that point pretty much enough of a mess that they either couldn't support hetairoi-grade cavalry anymore, or that whatever they could maintain was needed on the local front though ? IIRC the Seleucs had a major war with the Parthians only some half a dozen years before Magnesia... They apparently also picked up the cataphract idea during that one, and this new type of elite shock cavalry would obviously have hogged estates and other resources from the older hetairoi type - any idea of where those Seleuc catas at Magnesia were raised from, geographically ? I'll throw a guess that many of them would have been re-equipped hetairoi from the eastern regions, where the line between the xyston and the heavier kontos had probably also been blurring for a while.