Medieval Information

During the Dark Ages, many open-field battles took place. When an army lost a battle, normally it would have relieving forces to make an ordered retreat which would result in fewer losses. Nevertheless, many armies did not care or did not possess such forces which made the retreats much more deadlier resulting in immense losses for the retreating army.

Heavy cavalry was especially good for killing retreating forces as they could very hastily charge against the confused soldiers killing several units per trip.

Retreating armies usually had pikemen who could make the cavalry's job much harder, but the pikemen were usually the first to retreat so this type of defense was more of the exception rather than the rule.

One battle which changed the curse of the Scottish history illustrates perfectly this point. You may read more about it in my Bannockburn Battle article.