From the very beginning of recorded history, peoples and nations have sought to be powerful at sea. Those who did so recognised that there was something uniquely cost-effective about seapower, as compared to landpower, and that those nations best able to exploit its attributes profited hugely over those who did not. From the sixteenth to the twentieth centuries, the Europeans discovered, and were able to exploit, the huge advantage to be derived from the close association between the military and mercantile aspects of seapower. Geo-politicians such as Halford Mackinder have pointed out that many long-lasting empires were based on landpower not seapower. The German economic rise of the late nineteenth century and Russia's a little later on did not depend on seapower. The history of the law of the sea has been dominated by a central and persistent theme – the competition between the exercise of governmental authority over the sea and the idea of the freedom of the seas.