A knight is a person granted an honorary title of a knighthood by a head of state (including the pope) or representative for service to the monarch, the church, or the country, especially in a military capacity.

The concept of knighthood may have been inspired by the ancient Greek () and Roman . In the Early Middle Ages in Western Christian Europe, knighthood was conferred upon mounted warriors.Clark, p. 1. During the High Middle Ages, knighthood was considered a class of petty nobility. By the Late Middle Ages, the rank had become associated with the ideals of chivalry, a code of conduct for the perfect courtly Christian warrior. Often, a knight was a vassal who served as an elite fighter or a bodyguard for a lord, with payment in the form of land holdings. The lords trusted the knights, who were skilled in battle on horseback. In the Middle Ages, knighthood was closely linked with horsemanship (and especially the joust) from its origins in the 12th century until its final flowering as a fashion among the high nobility in the Duchy of Burgundy in the 15th century. This linkage is reflected in the etymology of chivalry, cavalier, and related terms such as the French title of . In that sense, the special prestige accorded to mounted warriors in Christendom finds a parallel in the in the Islamic world. The Crusades brought various military orders of knights to the forefront of defending Christian pilgrims traveling to the Holy Land.

In the Late Middle Ages, new methods of warfare – such as the introduction of the culverin as an anti-personnel, gunpowder-fired weapon – began to render classical knights in armour obsolete, but the titles remained in many countries. Holy Roman Emperor Maximilian I (1459–1519) is often referred to as the "last knight" in this regard;Sabine Haag (2014), Kaiser Maximilian I.: Der letzte Ritter und das höfische Turnier however, some of the most iconic battles of the Knights Hospitaller, such as the Siege of Rhodes and the Great Siege of Malta, took place after his rule. The ideals of chivalry were popularized in medieval literature, particularly the literary cycles known as the Matter of France, relating to the legendary companions of Charlemagne and his men-at-arms, the paladins, and the Matter of Britain, relating to the legend of King Arthur and his Knights of the Round Table.

Today, a number of orders of knighthood continue to exist within Christian denominations, as well as in several historically Christian countries and their former territories, such as the Roman Catholic Sovereign Military Order of Malta, the Protestant Order of Saint John, as well as the English Order of the Garter, the Swedish Royal Order of the Seraphim, the Spanish Order of Santiago, and the Norwegian Order of St Olav. There are also dynastic orders like the Order of the Golden Fleece, the Imperial Order of the Rose, the Most Ancient and Most Noble Order of the Thistle and the Order of St George. In modern times these are orders centred around charity and civic service, and are no longer military orders. Each of these orders has its own criteria for eligibility, but knighthood is generally granted by a head of state, monarch, or prelate to selected persons to recognise some meritorious achievement, often for service to the Church or country. The modern female equivalent of a knight in the English language is dame. Knighthoods and damehoods are traditionally regarded as prestigious.

Etymology The word knight, from Old English cniht ("boy" or "servant"), is a cognate of the German word Knecht ("servant, bondsman, vassal"). This meaning, of unknown origin, is common among West Germanic languages (cf Old Frisian kniucht, Dutch knecht, Danish knægt, Swedish knekt, Norwegian knekt, Middle High German kneht, all meaning "boy, youth, lad"). Middle High German had the phrase guoter kneht, which also meant knight; but this meaning was in decline by about 1200.William Henry Jackson. "Aspects of Knighthood in Hartmann's Adaptations of Chretien's Romances and in the Social Context." In Chrétien de Troyes and the German Middle Ages: Papers from an International Symposium, ed. Martin H. Jones and Roy Wisbey. Woodbridge: D. S. Brewer, 1993. 37–55.

The meaning of cniht changed over time from its original meaning of "boy" to "household retainer". Ælfric's homily of St. Swithun describes a mounted retainer as a cniht. While cnihtas might have fought alongside their lords, their role as household servants features more prominently in the Anglo-Saxon texts. In several Anglo-Saxon wills cnihtas are left either money or lands. In his will, King Æthelstan leaves his cniht, Aelfmar, eight hides of land.

A rādcniht, "riding-servant", was a servant on horseback.

A narrowing of the generic meaning "servant" to "military follower of a king or other superior" is visible by 1100. The specific military sense of a knight as a mounted warrior in the heavy cavalry emerges only in the Hundred Years' War. The verb "to knight" (to make someone a knight) appears around 1300; and, from the same time, the word "knighthood" shifted from "adolescence" to "rank or dignity of a knight".

An Equestrian (Latin, from eques "horseman", from equus "horse") was a member of the second highest social class in the Roman Republic and early Roman Empire. This class is often translated as "knight"; the medieval knight, however, was called miles in Latin (which in classical Latin meant "soldier", normally infantry).D'A. J. D. Boulton, "Classic Knighthood as Nobiliary Dignity", in Stephen Church, Ruth Harvey (ed.), Medieval knighthood V: papers from the sixth Strawberry Hill Conference 1994, Boydell & Brewer, 1995, pp. 41–100.Frank Anthony Carl Mantello, A. G. Rigg, Medieval Latin: an introduction and bibliographical guide, UA Press, 1996, p. 448.Charlton Thomas Lewis, An elementary Latin dictionary, Harper & Brothers, 1899, p. 505.

In the later Roman Empire, the classical Latin word for horse, equus, was replaced in common parlance by the vulgar Latin caballus, sometimes thought to derive from Gaulish caballos.Xavier Delamarre, entry on caballos in Dictionnaire de la langue gauloise (Éditions Errance, 2003), p. 96. The entry on cabullus in the Oxford Latin Dictionary (Oxford: Clarendon Press, 1982, 1985 reprinting), p. 246, does not give a probable origin, and merely compares Old Bulgarian kobyla and Old Russian komońb. From caballus arose terms in the various Romance languages cognate with the (French-derived) English cavalier: Italian cavaliere, Spanish caballero, French chevalier (whence chivalry), Portuguese cavaleiro, and Romanian cavaler. The Germanic languages have terms cognate with the English rider: German Ritter, and Dutch and Scandinavian ridder. These words are derived from Germanic rīdan, "to ride", in turn derived from the Proto-Indo-European root *reidh-.

History and evolution of medieval knighthood

Pre-Carolingian legacies

In ancient Rome, there was a knightly class Ordo Equestris (order of mounted nobles). Some portions of the armies of Germanic peoples who occupied Europe from the 3rd century CE onward had been mounted, and some armies, such as those of the Ostrogoths, were mainly cavalry.Petersen, Leif Inge Ree. Siege Warfare and Military Organization in the Successor States (400–800 A.D.). Brill (September 1, 2013). pp. 177–180, 243, 310–311. However, it was the Franks who generally fielded armies composed of large masses of infantry, with an infantry elite, the comitatus, which often rode to battle on horseback rather than marching on foot. When the armies of the Frankish ruler Charles Martel defeated the Umayyad Arab invasion at the Battle of Tours in 732, the Frankish forces were still largely infantry armies, with elites riding to battle but dismounting to fight.

Carolingian age In the Early Medieval period, any well-equipped horseman could be described as a knight, or miles in Latin. The first knights appeared during the reign of Charlemagne in the 8th century.Craig Freudenrich, Ph.D. As the Carolingian Age progressed, the Franks were generally on the attack, and larger numbers of warriors took to their horses to ride with the Emperor in his wide-ranging campaigns of conquest. At about this time the Franks increasingly remained on horseback to fight on the battlefield as true cavalry rather than mounted infantry, with the discovery of the stirrup, and would continue to do so for centuries afterwards. Although in some locations the knight returned to foot combat in the 14th century, the association of the knight with mounted combat with a spear, and later a lance, remained a strong one. The older Carolingian ceremony of presenting a young man with weapons influenced the emergence of knighthood ceremonies, in which a noble would be ritually given weapons and declared to be a knight, usually amid some festivities. These mobile mounted warriors made Charlemagne's far-flung conquests possible, and to secure their service he rewarded them with grants of land called benefices. These were given to the captains directly by the Emperor to reward their efforts in the conquests, and they in turn were to grant benefices to their warrior contingents, who were a mix of free and unfree men. In the century or so following Charlemagne's death, his newly empowered warrior class grew stronger still, and Charles the Bald declared their fiefs to be hereditary, and also issued the Edict of Pîtres in 864, largely moving away from the infantry-based traditional armies and calling upon all men who could afford it to answer calls to arms on horseback to quickly repel the constant and wide-ranging Viking attacks, which is considered the beginnings of the period of knights that were to become so famous and spread throughout Europe in the following centuries. The period of chaos in the 9th and 10th centuries, between the fall of the Carolingian central authority and the rise of separate Western and Eastern Frankish kingdoms (later to become France and Germany respectively) only entrenched this newly landed warrior class. This was because governing power and defence against Viking, Magyar and Saracen attack became an essentially local affair which revolved around these new hereditary local lords and their demesnes.

Multiple crusades and military orders

Clerics and the church often opposed the practices of the knights because of their abuses of women and civilians, and many, such as St. Bernard de Clairvaux, were convinced that Knights served Satan rather than God and needed reforming.

In the course of the 12th century, knighthood became a social rank with a distinction being made between milites gregarii (non-noble cavalrymen) and milites nobiles (true knights). As the term "knight" became increasingly confined to denoting a social rank, the military role of fully armoured cavalryman gained a separate term, "man-at-arms". Although any medieval knight going to war would automatically serve as a man-at-arms, not all men-at-arms were knights.

The first military orders of knighthood were the Knights of the Holy Sepulchre and the Knights Hospitaller, both founded shortly after the First Crusade of 1099, followed by the Order of Saint Lazarus (1100), Knights Templars (1118), the Order of Montesa (1128), the Order of Santiago (1170) and the Teutonic Knights (1190). At the time of their foundation, these were intended as monastic orders, whose members would act as simple soldiers protecting pilgrims.

It was only over the following century, with the successful conquest of the Holy Land and the rise of the crusader states, that these orders became powerful and prestigious.