heavy cavalry engaging heavy cavalry

[Sean Manning]

Btw, could you give a ref regarding the Bactrians and the Thessalians? I do not seem to be able to find it in my translation of Rufus.

Its Rufus, Historia Alexandri Magni, 3.9.1, 3.11.1-3, 3.11.13-15. Rufus says that the Bactrians rode over an ala of Thessalians with their impetus, a noun which medieval writers often use for the effect of a cavalry charge. He says that they were defeated because they let themselves get scattered in victory, and because the Thessalians made some sort of turning movement and attacked them while they were disordered. I believe that Arrian neglects this scene in his version of the battle (just like Rufus does not emphasize that the Macedonian phalanx had trouble crossing the river).

Arrian's version of the Granicus would be another interesting example of a hand-to-hand fight between cavalry. There may be something in the accounts of the Bactrian campaign, but I am not so familiar with the sources there.