During the Latin Middle Ages, as today, “tyranny” connotes the exercise of power arbitrarily, oppressively, and violently. Medieval thinkers generally followed in the footprints of early Christian theologians (e.g., Gregory the Great and Isidore of Seville) and ancient philosophers (especially Aristotle) regarding the tyrant as the very embodiment of evil rulership and thus as the polar opposite of the king, who governed for the good of his people according to virtue and religion. However, examination of the writings of some well-known and influential authors from ca. 1150 to ca. 1400—including John of Salisbury, Ptolemy of Lucca, William of Ockham, Bartolous of Sassoferrato, and Nicole Oresme—reveals three very diverse and distinct conceptions of tyranny, each of which justified the tyrant in one way or another.