MEDIEVAL WARFARE

Siege Warfare:  Defending and Capturing the Castle

Purposes of the medieval castle:
(1)  Residence of the lord, his family, and his retainers
(2)  Administrative center
(3)  Quarters for military garrison
(4)  Refuge for local population in times of danger
In all cases, a major function was to protect inhabitants against attack.  The need to afford protection led to enormous improvements in fortress architecture over the course of the Middle Ages.
The Cavalry vrs. Infantry Debate really involves two questions:
(1)  How, when, and why did cavalry become the principal striking arm of medieval warfare?
(2)  Did infantry truly retreat into insignificance in medieval armies?
The Nature of medieval warfare:
(1)  Most military activity in the Middle Ages did not involve large battles
(2)  Much more important were relatively small skirmishes, raids into enemy territory, and sieges
Chevauchee:  French word which translates literally as a "ride about."  (The comparable word in Spanish is "calbagada.")    It refers to the typical large raid launched into enemy territory with the purpose of destroying as much of that territory as possible, ultimately undercutting the enemy's ability to make war.  Only occasionally did the chevauchee lead to a major battle.
Poitiers (1356):  A major battle in the Hundred Years War (1337-1453) that grew out of a chevauchee when a large French army overtook the Black Prince, Edward Plantagenet, who was conducting a chevauchee in northwestern France.
The most important type of medieval warfare was almost certainly the siege.
Since sieges are conducted by infantry, not cavalry, it throws into question the whole idea that infantry became unimportant in medieval warfare.
Siege Techniques:
Mining:  digging under the enemy walls in an attempt to bring them down.  Conducted by infantrymen known as sappers. 
Two examples: 
Siege of Edessa (1144) conduted by the Moslem leader, Zengi
Siege of Limoge (1369) conducted by the Black Prince
War of the Two Pedros (1356-66):  a bitter war, but one almost devoid of battles
Many warriors are remembered at least in part for their conduct at a siege
Examples:
(1)  Godfrey de Bouillon:  leader of the First Crusade who took Jerusalem (1099)
(2)  Richard the Lionheart:  Third Crusade leader who took Acre (1191)
(3)  Bertrand DuGuesclin:  Constable of France in the Hundred Years war who called himself to the attention of the French king at the siege of Melun (1359)
Means of taking a castle that did not involve an assault:
(1)  Negotiating its surrender (especially one involving good terms to the defenders) (The siege of Melun in 1359 ended several days after DuGuesclin's fall in a negotiated surrender.)
(2)  Burning it down
(3)  Starving it out or cutting off/poisoning the water supply
(4)  Fomenting disease within the castle
Execution of the garrison usually (though not always) occurred after they had put up a considerable resistance.  In such a situation, it was considered acceptable military practice not only to kill the garrison, but also to sack the city, killing off the civilian population.
Famous examples of sacks that led to massacres:
(1)  Antioch (1097) and Jerusalem (1099) during the First Crusade
(2)  Acre in 1191 during the Third Crusade and again in 1291 at the final defeat of the crusaders
(3)  Bezier (1209):  Albigensian stronghold overrun by crusaders who listened to the advice of the papal legate, Arnold Amalric, "Kill them all, God will know his own."
(4)  Limoge (1369)
Castellan:  the man charged with defense of the fortress. 
A special problem presented itself when a castellan held a castle for a noble and it was besieged by their mutual overlord, the king.  Whom did you obey, your lord or his lord?
As castles came to be made of stone, fire proved less useful as a weapon.  On the other hand, fire continued to have a place in the assault:
(1)  Against parts of the castle that continued to be made of wood (floors and roofs)
(2)  Against hoardings
(3)  To burn "curtains" of timber, rope, and straw that were set up to help protect stone walls against striking projectiles
Principal example of finding a traitor to betray the castle or city under attack:  During the First Crusade, the Norman leader, Bohemond, took Antioch by finding an officer willing to sell out several of the towers.
Use of "biological warfare":  siege engines were employed to propel diseased corpses into the city in hopes of starting an epidemic. Principal medieval example:  in 1347, Mongols attacking a Genoese settlement on the Crimean peninsula north of the Black Sea sent corpses infected with the newly-arrived bubonic plague that was killing the besiegers over the walls.  The Genoese evacuated their settlements and took the disease with them back to Europe.  When they landed in Sicily and southern Italy in the final months of 1347, despite their being driven out by the inhabitants, plague made it ashore and in the following year (1348), overran most of Europe.  During the period referred to as the Black Death (1347-1350), between a quarter and a half of the European population was wiped out.
Major siege engines used in an attack on the castle:
1.  Artillery (trebuchet, catapult, ballista)
2.  Battering ram
3.  Siege tower