“This was far from the only damning judgment passed of King John” – Powers and Thrones (Dan Jones) https://bookshop.org/ebooks/quotes/00554cad-6255-4874-8ee4-46cd7dedafda

«Yet [the knight] William [Marshall] could not get along with John. The new king’s character was neatly summed up by a chronicler known as the Anonymous of Béthune. Although John was capable of lavish hospitality and generosity, noted the writer, adding that he gave out handsome cloaks to his household knights, John was otherwise “a very bad man, more cruel than all others, he lusted after beautiful women and because of this he shamed the high men of the land, for which reason he was greatly hated. Whenever he could, he told lies rather than the truth. . . . He hated and was jealous of all honorable men; it greatly displeased him when he saw someone acting well. He was brim-full with evil qualities.”54

This was far from the only damning judgment passed of King John, who between 1199 and 1216 enjoyed one of the least successful reigns in English history. Even a summary list of his failures runs quite long: John lost most of the Plantagenets’ lands in France (including the duchy of Normandy); he murdered Arthur of Brittany; he irritated Pope Innocent III to such a degree that he was excommunicated; he extorted so much money from his barons in taxes and semi-legal fines that he pushed many of them to the verge of either bankruptcy or rebellion; he wasted all the money he had plundered from his people on a hopeless war to regain his French lands; he drove his realm into a civil war, during which he was forced to grant a peace treaty circumscribing his royal powers, later known as Magna Carta; he reignited the civil war by renouncing Magna Carta and consequently suffered a full invasion of his realm by the heir to the French crown, Prince Louis; and in the end, he died, abandoned by most of his allies, having lost many of his crown jewels in the marshlands in eastern England known as The Wash.

To what degree precisely all of this was John’s fault is not our concern here. What is significant, though, is that the Anonymous of Béthune, who was probably in the service of a Flemish lord from that town, near Calais, saw John’s failings through an unmistakably chivalric prism. John was not merely incompetent, an unskilled leader, unlucky, or undiplomatic. He was also untruthful, dishonorable, lustful, untrustworthy, and spiteful. For as much as William Marshal’s biographer would portray his rise through life as the reward for his dedication to knightly virtues, so too would chroniclers like the Anonymous of Béthune ascribe John’s free fall through kingship as just deserts for his unchivalrous approach to life. Knightliness—or the perception of knightliness—could make or break a man in the twelfth and thirteenth centuries. It made William Marshal. It unmade King John.»

O btw, the Magna Carta, the thing we white people are so proud of. Like nobles facing down a king is somehow unique.