Military power sometimes works simply by virtue of its existence. It has its effect without being used. This is especially true of naval power.

If maritime supremacy goes unchallenged, there are no big battles to report. Because of this, naval power is often invisible, or at least little noticed. The Roman Empire provides a clear example. Everyone knows about the legions -the kit, the training, the discipline, the professionalism, their role in creating and defending the Empire. But what about the fleet?

In our special this issue, Marc DeSantis, author of a new book on the subject, argues that the founding of the Roman Navy, in the context of the mid 3rd century First Punic War, was a decisive event in Rome’s ascent to imperial greatness.

The war lasted a quarter of a century. The combined losses are estimated at 300,000 men and 1,200 ships. It was one of the greatest wars in Roman history, and the only one fought as much at sea as on land. And it launched Rome on its career of overseas conquest -a career underwritten by the maritime supremacy wrested from the Carthaginians between 264 and 241 BC.

Also this issue, we have Chris Bambery’s account of Prestonpans, the forgotten Jacobite victory of September 1745, Tom Farrell on Ireland’s divided loyalties during the First World War, and Sarah De Nardi’s analysis of the Italian Resistance in 1943-1945.