When called to battle during the Middle Ages in Europe, soldiers expected to be surrounded by unpleasant, if not downright unspeakable, sights. Much like the lives of medieval executioners, medieval soldiers witnessed blood, carnage, and death on an up-close-and-personal level. Accounts of the great medieval battles not only detail soldiers' lives and the conditions they faced, but also reveal the damage they inflicted on their enemies and noncombatants alike.
Weapons, tactics, and strategies mattered, of course, but so too did bravery, devotion to God, and fidelity to their lord. The facts of medieval warfare remain unique to the period, but reinforce the fundamentals of war in general. Back in the day, soldiers told themselves they fought for heaven's glory, but war was, is, and always will be hell.
Generally speaking, "campaign season" took place when the weather grew decent. While fighting never remained exclusive to warm summer months - sieges could last for months and extend well into winter - medieval lords typically called their men to battle after they planted the fields and before the harvest. Charlemagne issued orders each spring to gather his men.
When William the Conqueror gathered his men to invade England in 1066, he called them in summer only to be stalled by unfavorable winds. Eventually, the English troops awaiting William's arrival had to return home for their harvests, leaving King Harold vulnerable.
Campaigning during spring, summer, and early fall also meant more food available for men and horses, less need for firewood, and fewer terrain problems to contend with as battle approached.
Depending on the type of military battle you engaged in, you could bring your wife, mother, kids, and other members of your family along. This practice was prevalent during the Crusades, when thousands of people made their way from Western Europe toward Jerusalem. The First Crusade saw men set "forth with wife and child and laden with their entire household equipment" to fight on behalf of Christianity and attain a better life.
The dangers of taking the family along were apparent in Peter the Hermit's disastrous efforts to reach the Holy Land. Shortly after reaching Constantinople, his group of pilgrims ran afoul of a group of Turks - "going within the tents, they destroyed with the sword whomever they found, the weak and the feeble, clerics, monks, old women, nursing children."
Many of the wives who accompanied their husbands on later Crusades were aristocratic, including Richard the Lionheart's wife, Berengaria of Navarre. Berengaria joined her husband in Syria after marrying him in Cyprus in 1191, but was only there briefly. And since Berengaria never set foot in England, when Richard passed away eight years later she lost any titles she had gained by marrying him, making it difficult for her to regain the lands in her dowry.
Medieval weapons were meant to inflict ultimate damage, but not all wounds were fatal. Head injuries from maces, swords, and axes often led to brain damage and deformity, but might result in prestigious scars as well. Fatal wounds, like those discovered on the remains of soldiers who fought at the Battle of Towton in 1461, and battles near Stirling Castle between the 13th and 15th centuries, reveal the potential for a violent end. The bones show cuts, blows, and holes throughout the body, indicating a painful demise.
Medieval texts also speak to the brutality of war. Enguerrand de Monstrelet's account of the Battle of Agincourt in 1415 describes the aftermath, detailing how the English carried away their wounded while "several of the French, half dead and wounded, crawled away into an adjoining wood, or to some villages, as well as they could, where many expired."
In his De Re Militari, Vegetius stressed training, though formal training didn't exist during the early Middle Ages. Once troops gathered for a battle, they participated in drills and other exercises, but generally, they relied on the skills acquired over the course of their lives. Hunting built up horsemanship, not to mention weapon usage.
By the later Middle Ages, knights could build and demonstrate their military skills on the tournament circuit. Tournaments carried their own dangers, much like battle; Duke Leopold V of Austria died in a jousting accident in 1194, hardly a glorious way to go.