Roman Legionaries Vs. Medieval Heavy infantry

[Titus Manlius Verus]

I believe that people have forgotten that the Romans fought and defeated cataphract Calvary numerous times in their history. Compared to the Parthians, medieval kingdoms were Ill-disciplined, ill-supplied, and in most cases, were poorly equipped on the infantry level. In fact, many knights fought on foot, and made up only a fraction of an army's force. Additionally, many only fought out of duty to their lord. I believe it was William the first who scolded his knights for lack of effort in battle. He derided them saying that they were lazy and were more interested in showing prowess in the bedroom than on the battlefield.