One of the seminal figures of the late fourteenth century, Philippe de Mézières was born around 1327 as the twelfth and youngest son in a family of impoverished Picard nobility. He was schooled by the canons at the Cathedral of Notre Dame school in Amiens before taking up a career in arms under Luchino Visconti in 1345. He rose rapidly to serve six kings in various capacities: Andrew of Sicily; Alphonse XI of Castile; Hugh IV, Peter I, and Peter II of Cyprus; and Charles V of France, for whom he was not only royal counselor but also tutor to the future Charles VI. Two of the rulers he served—Andrew and Peter I—were assassinated during his tenure. A diplomat, Philippe represented the court of Cyprus at the papal court in Avignon, was a friend of Petrarch, and was given the keys to the city...