Parthian/Sassanid heavy cavalry use bamboo lances?

[Dan Howard]

If the couched lance technique had been in use for many centuries by many different peoples how do you account for the superiority shown by the heavy cavalry of the Normans and other Westerners against Byzantium from the 1060s and against the Middle Eastern Muslim peoples from the First Crusade onwards? Please do not say armour, because Western armour at this time, though heavy, was not as diverse or effective as the armour used by their Byzantine and Muslim foes.

The Byzantine princess and historian Anna Comnena stated: "For a Frank on horseback is invincible, and would even make a hole in the walls of Babylon". Franks were obviously doing something that contemporary Byzantine cavalry were not.

Their mail was superior to that of their opponents and it covered more of the body. Their horses were larger and better trained for shock tactics.

"He furnished them abundantly with arrows and exhorted them not to use them sparingly, but to shoot at the horses rather than at the Franks. For he knew that the Franks were difficult to wound, or rather, practically invulnerable, thanks to their armoured coats of mail. Therefore he considered shooting at them useless and quite senseless. For the Frankish defensive arms is this coat of mail, ring woven into ring, and the iron fabric is such excellent iron that it repels arrows and keeps the wearer’s skin unhurt." [Alexiad, VIII.8]