The accession of the Tudors to the throne of England marks an important period in our military history. The nation, after thirty years of furious internal war, during which it had lost all sense of national honour, began to settle down once more to a life of peace, and awoke to the fact that England was now no more than an insular power. France was lost to her except Calais, but Calais was something more than a mere sentimental possession. It was the bridge-head that secured to the English their passage of the Channel; and while it remained in the hands of an English garrison there was always the temptation to engage in Continental wars and to employ the army for purposes of aggression as well as of defence. Still the prospects of regaining the ancestral possessions of the Plantagenets in France seemed so hopeless that the English sovereigns might well doubt whether it were not now time to give the Navy the first and the Army the second place; and this question, already half decided by the keen good sense of King Henry the Eighth, was finally determined by the loss of Calais itself. There was, of course, always a frontier to be guarded on the Tweed, but with the cessation of expeditions to France, which had invariably called the Scotch armies across the border, there was no longer the same danger of Scottish invasion; and moreover, England and Scotland were now beginning to draw closer together. Thus it would seem that after the death of Queen Mary there should have been little reason for the existence of an English army, and indeed it will be seen that the national force became in many respects lamentably deficient. But meanwhile the wars of Europe changed from a contest between nation and nation to a death struggle between Catholic and Protestant. It was religion that drew the Scotch from their old alliance with the French to their former enemies the English; and it was religion which led the English to the battlefields of the Low Countries, where they learned the new art of war. The reign of the Tudor dynasty therefore falls for the purpose of this history into three periods, which are conveniently separated by the fall of Calais or the more familiar landmark of the accession of Elizabeth, and by the first departure of English volunteers to the Low Countries in 1572.