In one form or another, the subject of his impassioned pleading for peace among beings human, civilized, and Christian, had been long in Erasmus's mind. In his most celebrated single work, the Praise of Folly, he had bitterly attacked the attitude towards war habitual, and evilly consecrated by usage, among kings and popes. The same argument had formed the substance of a document addressed by him, under the title of Anti-Polemus, to Pope Julius in 1507. Much of the substance, much even of the phraseology of that earlier work is doubtless repeated here. Beyond the specific reference to Pope Leo, the other notes of time in the treatise now before us are few and faint. Allusions to Louis XII of France (1498-1515), to Ferdinand the Catholic (1479-1516), to Philip, king of Aragon (1504-1516), and Sigismund, king of Poland (1506-1548), are all consistent with the composition of the treatise some years earlier. At the end of it he promises to treat of the matter more largely when he publishes the Anti-Polemus. But this intention was never carried into effect. Perhaps Erasmus had become convinced of its futility; for the events of the years which followed soon showed that the new Augustan age was but a false dawn over which night settled more stormily and profoundly than before. For ten or a dozen years Erasmus had stood at the head of European scholarship. His name was as famous in France and England as in the Low Countries and Germany. The age was indeed one of those in which the much-abused term of the republic of letters had a real and vital meaning. The nationalities of modern Europe had already formed themselves; the notion of the Empire had become obsolete, and if the imperial title was still coveted by princes, it was under no illusion as to the amount of effective supremacy which it carried with it, or as to any life yet remaining in the mediaeval doctrine of the unity of Christendom whether as a church or as a state. The discovery of the new world near the end of the previous century precipitated a revolution in European politics towards which events had long been moving, and finally broke up the political framework of the Middle Ages. But the other great event of the same period, the invention and diffusion of the art of printing, had created a new European commonwealth of the mind. The history of the century which followed it is a history in which the landmarks are found less in battles and treaties than in books.