Map of the Roman fleets and major naval bases during the Principate, 27 BC to AD 284. (public domain image)

(6) MARE NOSTRUM – IMPERIAL LAKE

Mare nostrum, literally “our sea” in Latin, connoting the core of the Roman Empire – its complete control of the Mediterranean Sea and coastline, as a perfect fusion of territorial and maritime empire.

No other state has come close to that fusion of territorial or maritime empire for total domination of a maritime body of water – a sea, let alone an ocean – although some maritime empires or naval powers have come close in terms of naval predominance, which we’ll come back to with that term of imperial lake. Speaking of lakes, I’m obviously excluding those bodies of water such as lakes or rivers that are essentially internal to a single nation or state, hence that qualifier of maritime which typically connotes sea or ocean.

The Roman Empire had complete naval predominance that was effectively a monopoly throughout its imperial period – in the absence of any maritime enemy in the form of a rival state, although the Roman navy still had to contend with piracy and barbarian incursions that were essentially also piracy until the Vandals managed to escalate to being a rival naval state.

What made the Roman mare nostrum distinctive was its total control of the coastline as territorial empire as well as naval power, and the classical Roman Empire remains the only state in history to have controlled the entire Mediterranean coast. Other states – the eastern Roman empire, the Arab caliphates, the Ottoman empire, and the Axis powers – have come close to or contended for that control of the Mediterranean coastline but fell short or were successfully contested. Fascist Italy even revived the use of the term in its claim to Mediterranean empire and Roman succession.

However, as I said, other maritime empires or naval powers have come close to the same naval predominance over a body or bodies of water, although they have tended to confine their control of coastlines to islands or key points as strategic bases or areas of command.

Hence, the informal use of the term lake to connote that naval predominance, mirroring the use of the term mare nostrum – and has indeed been substituted for it, describing the Mediterranean as a “Roman lake”.

For example, I have seen the Indian Ocean and Pacific Ocean described as a Portuguese lake and Spanish lake respectively at the outset of the period of European maritime exploration, although both were soon encroached upon or contested by other European maritime powers. One of those powers – the British – effectively displaced Portuguese or other naval powers to claim the Indian Ocean as a “British lake”, although really British naval predominance in the nineteenth century was such to make all the world’s oceans (or World Ocean) their lake. The Pax Britannica was essentially naval, something that was inherited by its American successor.