The English scholar John of Salisbury was a major intellectual of the twelfth century whose contributions to the fields of education, grammar, political theory, and rhetoric are well-known. His significance is amplified further in John of Salisbury: Military Authority of the Twelfth-Century Renaissance, in which John D. Hosler examines his heretofore overlooked contributions to the ideals and practice of medieval warfare. This book surveys an array of military topics present within John’s extant corpus, including generalship, strategy, tactics, logistics, military organization, and training; it also collates John’s military lexicon and charts the influence of classical texts upon his conceptualization of war. John of Salisbury, it argues, deserves inclusion in the roll-call of military theoreticians and writers of pre-Reformation Europe.