Medieval Tactics

During the true medieval period, investment was the only viable method for dealing with a fortification of any size. Without gunpowder (and without magic, of course), armies had no practical means of breaching walls any stronger than log palisades. True, siege engines such as catapults and ballistae had been used by the Romans, but even these weren’t overly effective against the stone curtain wall of a castle. Also, investments of the medieval period were usually undertaken by smaller-and frequently less-organized-groups than were later sieges. Such groups would rarely have brought siege engines along with them, have access to them after they reached the target, or know how to build them.

The usually smaller size of medieval siege armies had another consequence: there were simply insufficient troops to set up a complete cordon around the fortification. Instead, the attacker would typically just block off all gates and other portals into a castle, concentrating its forces at these key points. A sensible general would place a picket line of soldiers to keep watch on the rest of the building. Even so, it would usually be possible for someone inside the castle to escape at night-either over the wall or through a concealed passage and flee the area to summon help.

The attacker’s purpose, of course, is to prevent resupply and reinforcement to the castle under siege. Its effectiveness depends largely on the castle’s level of supply when the investment was laid. Most castles are built around a well of some kind; unless the attackers are able to poison or otherwise eliminate this well, thirst should not be a problem for the defenders. On the other hand, food soon will become a problem.

The level of supply varied widely for historical castles. Forts on the border between England and Wales were traditionally stocked with enough food for two months; Krak des Chevaliers, a Crusader castle in what is now Syria, was provisioned for a full year. Other castles, particularly those whose garrisons didn’t expect imminent attack, might have had considerably lower levels of supply.