Sometimes, it is true, the operations of military heroes have been on such a prodigious scale as to make very serious inroads on the population of the greatest states. Napoleon for instance, on one occasion took five hundred thousand men out of France for his expedition to Russia. The campaign destroyed nearly all of them. It was only a very insignificant fraction of the vast army that ever returned. By this transaction, Napoleon thus just about doubled the annual mortality in France at a single blow. Xerxes enjoys the glory of having destroyed about a million of men--and these, not enemies, but countrymen, followers, and friends--in the same way, on a single expedition. Such vast results, however, were not attained in the conflicts which marked the reigns of Elizabeth and Philip of Spain. Notwithstanding the long-protracted international wars, and dreadful civil commotions of the period, the world went on increasing in wealth and population, and all the arts and improvements of life made very rapid progress. America had been discovered, and the way to the East Indies had been opened to European ships, and the Spaniards, the Portuguese, the Dutch, the English, and the French, had fleets of merchant vessels and ships of war in every sea. The Spaniards, particularly, had acquired great possessions in America, which contained very rich mines of gold and silver, and there was a particular kind of vessels called _galleons_, which went regularly once a year, under a strong convoy, to bring home the treasure. They used to call these fleets _armada_, which is the Spanish word denoting an armed squadron. Nations at war with Spain always made great efforts to intercept and seize these ships on their homeward voyages, when, being laden with gold and silver, they became prizes of the highest value. Things were in this state about the year 1585, when Queen Elizabeth received a proposition from the Continent of Europe which threw her into great perplexity. Among the other dominions of Philip of Spain, there were certain states situated in the broad tract of low, level land which lies northeast of France, and which constitutes, at the present day, the countries of Holland and Belgium. This territory was then divided into several provinces, which were called, usually, the Low Countries, on account of the low and level situation of the land. In fact, there are vast tracts of land bordering the shore, which lie so low that dikes have to be built to keep out the sea. In these cases, there are lines of windmills, of great size and power, all along the coast, whose vast wings are always slowly revolving, to pump out the water which percolates through the dikes, or which flows from the water-courses after showers of rain.