The Rhine has had much to do with the history of Europe. Even in the times of the Romans the Rhine had its important cities and towns. Caesar led his soldiers along its banks; Charlemagne, another great conqueror, fought many battles near it; and Napoleon Bonaparte marched his armies back and forth across it. There is hardly a foot of the Rhine which has not its notable history, and every town and castle we pass, if it could speak, might tell an interesting story. From the Rhine a boat may pass by means of canals into the Danube. The river is internationalized as far as navigable.