Why couldn't Byzantine cataphracts charge in the same way that Frankish/Norman heavy cavalry could?
As far as I know, Byzantine lancers were actually more capable at charging than Frankish, or Norman cavalry at least as shock troops. I say this because they have been in the Byzantine army for a long time, and became an essential part of Byzantine armies. Norman or Frankish cavalry were both rather new, and they were still being developed. Generally Norman cavalry while powerful in its own right were not supposed to be used as shock troops. They generally would pepper the enemy with javelins, and skirmish with them a bit. Then if they managed to get the enemy to break formation, they would single out groups of infantry, and run them down. They only ever charged like this after a break in the formation was achieved where as true shock cavalry broke enemy formations by charging them in the rear, or sometimes from the front still able to achieve deadly results even if the enemy is in formation given the correct circumstances.I guess Norman cavalry was a sort of jack of all trades kind of unit. You could use them as shock troops, but it was not their strong suit. While it may be true that Byzantine lancers were generally superior, I think Norman cavalry would be just as capable of winning a battle used properly.
Why didn't Darius III use a cataphract to strike Alexander's companion?
The Macedonians were the pioneers of the kind of shock cavalry tactics that all others would later develop. The persian cavalry was first and foremost a skirmisher force. While highly skilled soldiers, they did not drill and fight as a group the way the companions did.There were cataphracts in Darius’ army, and even in the armies preceeding him, but we don’t know exactly how they fought. It’s likely they fought as all other eastern cavalrymen fought, as individual soldiers - albeit very heavily armored individual soldiers.So the short answer is; Alexander probably faced many cataphracts but they were all defeated.
Was Alexander the great defeated by the son of Porus in a one on one fight?
Porus is overhyped, he was pretty easily defeated, just not on same excessively easy scale upon which the chronicles would dictate he earlier defeated the Persians. Without the comparable ease with which he earlier walked through the Persians, this would be recorded as a one sided victoryHe was more of someone that posed a good candidate to be a vassal than anything else.His son reportedly died in battle, anything beyond that is tabloid content written to entertain. He died, Alex didn't. That's really all we know, and honestly that's how it'll remain. Mind you there is no actual archaeological evidence nor contemporary writings on Alexander nor Porus. So while highly unlikely… it is possible they're all made up anyway. I mean nobody knows where this battle took place, let alone the city that was founded in that spot… pretty big archaeological gap right there and it's not for lack of searching…One thing though, Alexander would have always been surrounded by his personal guards, utterly impossible for anyone to ever get a chance to fight him in a duel. Only situation was when he eagerly charged over a wall and the ladders broke so he was somewhat isolated with only 2 guards for a little while. Most dire situation he ever faced, still had two guards protecting him and an entire army desperately trying to join him. Even if Alexander insisted on a one on one battle there's simply no way his guards would have allowed it.Alexander suffered many injuries but mostly from missiles. His personal guards never would have allowed any one on one fight to occur. In fact most recorded arguments he had with anyone usually involved them telling him they wanted him to lead from the rear and stay out of danger entirely.