Being a miles did not mean being a vassal, that is, an individual who had been granted lands in exchange for military service. Initially many knights were soldiers in the court of a great lord who provided a livelihood and the accouterments necessary to fight on horseback. Naturally the people selected combined physical vigor and fighting skill with fealty and homage to the lord. The profession of knighthood attracted those who could find the weapons, armor, and horses necessary; as such, it became the refuge of the younger sons of a lord to whom the future may have seemed financially bleak (by custom, only the firstborn son inherited most of the father’s lands). As Duby claims, knighthood was the profession of youth in search of adventure, prestige, and fortune, which they expected to receive from war or sometimes from marriage to a rich woman. Initially it attracted not only the sons of the lower nobility but also better-off peasants who owned the instruments of a heavy cavalryman. This was the case of Guigonnet of Germolles, a rich peasant of the twelfth century. Guigonnet had his living quarters not in a tower or a fortified manor or castle, like the nobility, but in an agricultural center, where the products of the land—wheat, wine, fruits—were gathered. What distinguished him from the other peasants was his higher standard of living. Probably he did not work the land with his own hands anymore; he had subordinates to do that. Moreover, he spent time hunting like the aristocrats and belonged to religious organizations, where he met social superiors. But the most important aspect of his life was that at times he wore the knightly weapons and armor that he owned, rode his strong horse, and joined the other knights.
Guigonnet is obviously the exception, even at the emergence of knighthood….
— Barbarians, Marauders, and Infidels, p. 173
[El Cid confronts the soldiers taking Prince Alfonso to the dungeons of Zamora.]El Cid:Will you give me your prisoner, or must I take him?Guard Leader:[incredulous] There are thirteen of us, and you are alone.El Cid:What you do is against God’s law. Were you thirteen times thirteen, I would not be alone!
— “El Cid” (1961)
That last line is a declaration of a D&D paladin, if there ever was one.
Fighting as a knight involved expense that became greater over time. In the twelfth century [C.E.] the knight’s basic equipment (horse, helmet, hauberk, and sword) required the annual revenue of 150 hectares. Three centuries later it cost the yearly income of 500 hectares. The horses alone of Gerard de Moor, Lord of Wessegem, amounted in 1297 to 1,200 livres tournois….
— Barbarians, Marauders, and Infidels, p. 177
Jean [de Carrouges]…held the rank of squire. Rather than the “gallant youth” this term often brings to mind, he was a battle-hardened veteran already in his forties, one of those “mature men of a rather heavy type—knights in all but name.”
By 1380 [C.E.], Jean…commanded his own troop of squires, numbering from four to as many as nine, in the campaigns to rid Normandy of the English. In war he sought to burnish his name and enrich himself by seizing booty and capturing prisoners to hold for ransom, a lucrative business in the fourteenth century. He may also have sought a knighthood, which would have doubled his pay on campaign…. [A] knight’s daily pay on campaign was one livre, while a squire received half that.
— The Last Duel, Chapter 1
A squire would not be knighted if he could not afford to maintain that higher station. Thus the drive for booty and ransom.