There's never been a mention of camels used as warmounts in historical sources until the Arab conquest in the 7th century.

However Herodutus mentions camels as the savoiur of Darius the First's invasion of the Scythians c.512 BC. Under attack from the tribemen, he ordered the camels used for supplying his troops to be placed at the point of attack. The unusual smell froced the Scythian horses to lose their composure and save his failed plan.

"Kill them all. God knows his own."
- Albigensian leader during their 13th century crusade against 'heretics'