Evaluating the real life historical behavior of knights in comparison to this ideal is problematic and complicated to say the least. While there were many Medieval and Renaissance knights who were considered to be paragons of chivalry by their country or even internationally, very often AHeroToHisHometown would be in effect and opinions would depend on who you asked. To take some examples from UsefulNotes/TheHundredYearsWar, Theatre/HenryV of England is often held up as a patriotic hero for his bravery at Agincourt, but the fact that he ordered the execution of French prisoners in the middle of the battle and subsequently committed what might be called atrocities during the [[TheSiege siege of Rouen]] casts a darker light on him. You also might find that some French knights would have considered [[UsefulNotes/TheHouseOfPlantagenet Edward III and Edward the Black Prince]] to be [[WorthyOpponent worthy opponents]], but the French peasants whose lands they [[RapePillageAndBurn ravaged]] would have had a less charitable opinion of them. When such characters are cast as the good guys in a modern work they will often get a HistoricalHeroUpgrade that removes these morally grey aspects of their deeds.
There is also a certain amount of ValuesDissonance because the modern popular understanding of chivalry prevalent since Victorian times is to some extent a distortion of what it meant in medieval times to the knights who practiced it. Today the word is usually associated with courtly manners, mercy and fair play in warfare, and protection of women and the weak, but we must not forget that first and foremost it was an ideal of behavior for aristocratic warriors meant to encourage military prowess. CourtlyLove for example, while genuinely important, was often described more as an incentive for a knight to try to distinguish himself in tournaments and warfare than as an end in and of itself. Modern readers of chivalric literature are often surprised at its sheer emphasis on the ability to kick ass and perform awesome feats, as opposed to the finer points of etiquette. In terms of warfare it was mainly concerned with relations between social equals, such as the rules for knights ransoming each other, and did not apply equally to common footmen or enemy noncombatants. Indeed, it was by no means as expansive as UsefulNotes/TheLawsAndCustomsOfWar, and in comparison was a loose set of guidelines for the warrior elite's martial ethic as opposed to some kind of law agreed to by international treaty. Therefore, the French felt justified in flying the ''Oriflamme'' banner signifying no quarter when the nation was threatened, and it was also considered more or less within the norms of warfare to [[LeaveNoSurvivors butcher the defenders]] of a town or castle who had refused a chance to surrender. Even within these surprisingly broad guidelines, there were many knights who were essentially unscrupulous [[PrivateMilitaryContractors mercenaries]] or criminals dignified by horse, armor, and a noble title.
All this should not be taken to mean that there were no knights who even today could be seen as examples of good behavior or at least honor in battle, as the RealLife section hopes to show. Perhaps it is best to describe Chivlary as an ideal to which most knights aspired, at least publicly, and conformed to in varying degrees.