This chapter examines naval and trade competition in war and peace between England, Denmark-Norway, and Sweden-Finland, roughly from the peace of Westphalia in 1648 to the Congress of Vienna in 1814–15, although with most focus on developments in the eighteenth century. We compare the naval and mercantile fleets of all three empires to find possible reasons for their divergent paths, and why both Denmark-Norway and Sweden-Finland declined as military powers in Northern Europe, whereas England dramatically increased its military and naval presence across the globe. We find that Britain benefited from a growing state which continued to fund and increase the size of the navy throughout the eighteenth century, whereas the Scandinavian kingdoms appear to maintain similar sizes of their navies and even decrease the amount of tonnage in their fleets by the beginning of the nineteenth century. Simultaneously, the merchant fleet of England dramatically expanded in size, while Sweden’s ultimately stagnated by the end of the eighteenth century. In effect, the combination of stagnating navies and mercantile fleets caused the two Scandinavian empires to decline while Britain grew into the largest empire in the world by the mid-nineteenth century.