An interesting account of two duels from Procopius between the Persians and Byzantines, one of which included a head-on collision by both combatant’s horses.
By Nicholas Petrou, Historian and member of the Academy of Historical European Martial Arts ‘Leontes’
“But one Persian, a young man, riding up very close to the Roman army, began to challenge all of them, calling for whoever wished to do battle with him. And no one of the whole army dared face the danger, except a certain Andreas, one of the personal attendants of Bouzes, not a soldier nor one who had ever practiced at all the business of war, but a trainer of youths in charge of a certain wrestling school in Byzantium. Through this it came about that he was following the army, for he cared for the person of Bouzes in the bath; his birthplace was Byzantium. This man alone had the courage, without being ordered by Bouzes or anyone else, to go out of his own accord to meet the man in single combat. And he caught the barbarian while still considering how he should deliver his attack, and hit him with his spear on the right breast. And the Persian did not bear the blow delivered by a man of such exceptional strength, and fell from his horse to the earth. Then Andreas with a small knife slew him like a sacrificial animal as he lay on his back, and a mighty shout was raised both from the city wall and from the Roman army.”
“But the Persians were deeply vexed at the outcome and sent forth another horseman for the same purpose, a manly fellow and well favoured as to bodily size, but not a youth, for some of the hair on his head already shewed grey. This horseman came up along the hostile army, and, brandishing vehemently the whip with which he was accustomed to strike his horse, he summoned to battle whoever among the Romans was willing. And when no one went out against him, Andreas, without attracting the notice of anyone, once more came forth, although he had been forbidden to do so by Hermogenes. So both rushed madly upon each other with their spears, and the weapons, driven against their corselets, were turned aside with mighty force, and the horses, striking together their heads, fell themselves and threw off their riders. And both the two men, falling very close to each other, made great haste to rise to their feet, but the Persian was not able to do this easily because his size was against him, while Andreas, anticipating him (for his practice in the wrestling school gave him this advantage), smote him as he was rising on his knee, and as he fell again to the ground dispatched him. Then a roar went up from the wall and from the Roman army as great, if not greater, than before; and the Persians broke their phalanx and withdrew to Ammodios, while the Romans, raising the paean, went inside the fortifications; for already it was growing dark. Thus both armies passed that night.”