heavy cavalry engaging heavy cavalry

[Frank]

If you look to the formation of some battles, e.g. Cannae, the job of the cavalry was, to defeat the enemies cavalry and then flank the infantry. So obviously cavalry fighting each other was rather the norm than the exception imho.

Unfortunately, I have no clue, how exactly Hannibals numidian cavalry defeated the roman cavalry at Cannae. Which was the beginning of the desaster.

I remember, that the romans often used mixed forces. So the cavalries job was to just hold the enemies cavalry, until nearby light infantry could close up and slaughter them. Caesar vs. Pompeius was such a fight, if I remember right. Or these famous palaestinian clubmen slaughtering cataphracts in late empire. Or the early german cavalry, which sometimes used 2 men on 1 horse. So the tactics might have been pretty versatile and situational.

And what does cavalry phalanx mean? Imho, it works best with heavy cavalry. But this was rather seldom and low numbers, even in the parthian cavalry or the late roman cavalry. And they always fighted together with horsed archers or light cavlry. Heavy cavalry without light cavalry support was propably just a sitting (dead) duck in ancient times.