Between the years 1560 and 1721, the Swedes endeavored to turn the Baltic Sea into a Swedish lake. Generations of young men perished in a seemingly end­less series of wars. How was it possible for an insignificant country on the outskirts of Europe, with small cities and a scant population, to de­velop into a great power? Convinced that God was on their side, the army marched across the ice of a frozen sea to take the enemy by surprise.