In laying down a policy of naval defense, however, it is not necessary to consider these three parts separately, because no nation can ever tell whether in the distant future its naval defense will have to be used directly for any one of the three, or for all. In general terms, it may be stated that in nearly all naval wars the fleet has been used more for the defense of the nation's policy than for the actual defense of the coasts or the trade routes. This does not mean that there has never been a bombardment or invasion, or that the defense of trade routes may not have been the cause of the war itself; but it does mean that in actual wars bombardment or invasion has been rare, the capture of merchant vessels has played a minor part, and the deciding events have been battles between two fleets, that were often far from the land of either. Owing to the fact that within modern times most of the important countries of the world have been those of continental Europe, with frontiers contiguous, and in fact identical, the defense of a country has been largely committed to the army, and most of the wars have been on land. The country standing in exception to this has been Great Britain, whose isolated and insular situation demanded a defense that was strictly naval. The tremendous advance in recent times of the engineering arts, by which ships became larger and faster, and able to carry more powerful and accurate guns than ever before, has enhanced the value of naval power and enabled Great Britain to reach all over the surface of the earth, and become more powerful than any continental nation. Thus she has made out of the very weakness of her position a paramount tower of strength. Naval defense was taken up systematically in Great Britain in the eighth century by King Offa, to whom is credited the maxim, "He who would be secure on land must be supreme at sea"; but it must have dropped to a low ebb by 1066, for William of Normandy landed in England unopposed. Since that time Great Britain's naval defense, committed to her navy, has increased steadily in effectiveness and power, keeping pace with the increase in the national interests it defended, and utilizing all the growing resources of wealth and science which the world afforded. Until the present crisis, Great Britain's naval defense did its most important work during Napoleon's time, when Great Britain's standing, like the standing of every other European nation, was subjected to a strain that it could hardly bear. So keenly, however, did the nation and the nation's great leader, Pitt, realize the situation that the most strenuous measures were adopted to keep the navy up, press-gangs even visiting the houses of subjects of the King, taking men out and putting them by force on board his Majesty's ships. But the British navy, even more than the British army, brought Great Britain safe out of the Napoleonic danger, and made the British the paramount nation of the world.