Who gets it: Cappadocia

Oh great king, beloved as thy are by the gods. You have made our realm great and beautiful. All the Iranians now listen to your word, all of Anatolia respects you, and all of the Greeks fear you. The superior godddess, Ma, has revealed to me, the highes priest in this land, how we can become invincible. In a dream, I saw a rider clad in shining iron, perched atop an armoured horse. The Sarmatians call it cataphracts, and they shall now be yours!

It fires when at least 50 battles have been fought by Cappadocia.

The game checks this at the end of every round.

3 units can be recruited once it fires:

Unit	Who can raise it
Cappadocian Cataphracts	Free Peoples
Cappadocian General's Bodyguard (Late)	Free Peoples
Cappadocian Noble Cavalry	Free Peoples

Units already in your armies are converted:

Before	After
Cappadocian General's Bodyguard	Cappadocian General's Bodyguard (Late)

1 unit can no longer be recruited:

Unit	Who can raise it
Cappadocian General's Bodyguard	Free Peoples