The knight emerged in Europe in the 9th century, when central governments were weak and there was little protection from bandits, sea raiders, and neighboring lords set on plunder. Each village, city, or monastery required protection by armed men. The most effective warriors in that period were armored cavalrymen. The introduction of the stirrup into Western Europe in the 8th century had made it possible for cavalrymen to use their weapons with tremendous striking force. The armor of the perioda chain mail tunic and conical helmet with nose guardmade the cavalryman even more formidable.
Nobles vied for the service of these warriors and provided them with grants of land. By the 11th century the English were using the term knight for the armored cavalryman. In France a knight was a chevalier; in Spain, a caballero, from the Spanish caballo, horse; in Germany and Austria, ritter, from German ritt, ride.
In the 12th century the adoption in England of the longbow and in the rest of Europe the crossbow, both powerful weapons that shot missiles that easily penetrated chain mail, threatened the supremacy of the knight. In the 13th century knights began wearing plate armor in combination with chain mail. The amount and thickness of the armor was gradually increased, as crossbows and longbows increased in effectiveness, so that by the 15th century a knight was completely encased. The knight was helpless on foot and when mounted could only move ponderously.
The Battle of Crcy (1346), during the Hundred Year's War fought between France and England, was a turning point in the use of knights in warfare. The English infantry, armed with longbows, easily defeated a French cavalry force three times its size, massacring 1,500 knights and nobles.
In the 14th century the use of infantrymen armed with pikes and fighting in close formation doomed the knight. Swiss pikemen spectacularly demonstrated their effectiveness when in a series of battles during 147477 against Charles the Rash of Burgundy they destroyed every heavy cavalry force sent against them. Shoulder-fired guns by the middle of the 15th century added to the effectiveness of the infantry.
By the end of the 15th century the knight had become obsolete, as countries established professional armies of infantrymen.