Finally, the mediæval was no fool. I have made this point in my first chapter; nevertheless, I repeat it here. We have seen that the importance of cavalry and of fortification, especially of castles (i.e., small highly-fortified points) resulted not from folly, but from the conditions of the time. Social and political conditions, again, were unfavorable to regular discipline, but no more so than in our own American Revolution. Less so, in fact. It is true that there was no regular study of war as an art. Nevertheless, our modern staff colleges could not easily improve on the decisions of many mediæval commanders. Even the lack of maps on which modern staff work is built up did not necessarily blind the eye of the commander operating in familiar or partially friendly country. The men of the Middle Ages sometimes show the power of sizing up the strategic essentials of a large theatre of war which they had never seen, and had never even seen mapped. For instance, take the case of Philip Augustus’s advice to his son with regard to the campaign of 1216 in England, that is that the Prince should first of all seize the castle of Dover which commanded the English terminus to the shortest possible sea route between England and France. In the present instance, the mobilization point and the line of march were intelligently chosen. It was clearly out of the question to cross the “Massif Central,” the mountains of Auvergne, since armies are compelled to seek the lines of geographical least resistance, and must avoid, whenever possible, thinly peopled districts which cannot keep them in food and shelter. The choice which faced the leaders of the Crusade was whether to outflank the mountainous country by the west or by the east. It is only a guess, but I think that the decision to march by the easterly route was mainly for political reasons. To march by the west would have brought the crusading army close to territory still held by John of England. That monarch was still firmly planted on both sides of the lower Garonne, and had even held on to parts of Poitou well to the north of that river. The much widowed Raymond of Toulouse had married John’s sister Joan, who had since died. John had broken with the Pope over the candidacy of Stephen Langton, later of Magna Charta fame, for the archbishopric of Canterbury; and when Innocent had replied by interdicting all England, John had been able to compel most of the English clergy from enforcing the sentence. Since the Crusade was obviously directed against Raymond, John might move. It would be well, therefore, for the Crusaders not to give him an opportunity of falling upon their flanks or rear while marching south on the westward route.