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In page Knight:

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Knights of the late medieval era were expected by society to maintain all these skills and many more, as outlined in Baldassare Castiglione's The Book of the Courtier, though the book's protagonist, Count Ludovico, states the "first and true profession" of the ideal courtier "must be that of arms."[4] Chivalry, derived from the French word chevalier ('cavalier'), simultaneously denoted skilled horsemanship and military service, and these remained the primary occupations of knighthood throughout the Middle Ages.