In the previous video we discussed the beginning of the reforms of Philip II and his mighty Macedonian Sarissa Phalanx. But Alexander's father did not stop there, also reforming his Companion Cavalry and his light Prodromoi cavalry and this video explains the tactics used by the new cavalry units, their weapons and armor, their battle roles and how they were formed. Philip also employed an engineer corp, led by Polyidus. Polyidus and his successors would create and improve many siege weapons that helped Philip and Alexander in their conquests.