--> Salve os,
For a equestrian history student this period - roughly 2300 BC to 330BC - 'starts with a big bang': the very first 'book' (part of the Hittite Horse tablets) on horse conditioning and training by a Mitanni (Hurrian) horsemaster (term 'assussanni' that contains Indo-Aryan word for horse - *asva) named Kikkuli who was most likely working for a Hittite king at Hattusa during XV century BC .
The text describes 184 day training of a stallion* or gelding* period (at least 7 months), that started during the autumn with feed and water management, stable treatments and bitting and harnessing until advanced endurance training when harnessed with another stallion or gelding to a chariot's yoke. While we use a generic name 'Kikkuli text' actually the training manual was a combination of Hurrian and Hittite trainers knowledge. The text contains some very interesting Indo-Aryan technical language (not used by the Hittites themselves, who used their own Indoeuropean language) and these terms talk about technical aspects of chariot horse training – eg, plaiting of horses' tails before yoking them to the chariot. There are also names for horse colors – reddish brown, grey, reddish yellow, greenish yellow etc. This color information later shows up in the Mittani records and Egyptian too – reddish, black etc usually sires (stallions) are depicted and often their coat is described in their names (eg curly hair, felt hair etc). Interestingly enough it does not give any information on actual war horse chariot training for battle, and the first known text on war horse training for battle is Xenophon's Peri hippica (IV century BC).