Second taking of Chusan, China, 1 October 1841, during the First Opium War, painted by Edward H. Cree (public domain image)

(2) MARITIME EMPIRE

“A state with primarily maritime realms, an empire at sea or seaborne empire”, sometimes known by the fancy term of thalassocracy, with the European empires of modern history as maritime empires par excellence, the British Empire most of all.

Pro tip for European empires in modern history – you can have a maritime empire, or you can strive for continental domination, but you can’t do both. Just ask Spain, France and Germany.

The obvious counterpart of the territorial empire annexed or conquered on land contiguous with the imperial nation, the maritime empire conquers its subject territory or projects its imperial reach by naval power and transport, typically focused on trade routes and strategic ports.

Maritime empires are something of the exception to the rule – the rule that is, that most empires are territorial, sometimes known by the fancy term of tellurocracy. However, I’d say most empires have at least some maritime element, even those that are otherwise predominantly or mostly territorial – extending to some element of naval power and maritime trade or conquering some island territory along their coastlines. Even early Mesopotamian and Egyptian empires relied on river transport, although I’d say that’s pushing the definition of maritime empire too far.

Some empires are more maritime than others – with the empires in top rank of maritime empires as those in which their territory is entirely or almost entirely not contiguous with the imperial nation and typically at some oceanic distance. As I said, the modern European colonial empires are the archetypal examples of maritime empires, hence the British and Spanish empires are the archetypal maritime empires among my top ten empires.

Some empires are curious hybrids of territorial and maritime empires, such as my top empire, the Roman empire – despite our usual perceptions of it as the former with its famed legions and roads (as well as its contiguous appearance on a map), the Mediterranean was the lifeblood of its internal lines of communication. It almost literally had to slap its navy together in the First Punic War against the maritime empire of Carthage – and even then, designed it with the boarding ramp known as the corvus to transform sea battle into a form of land battle. However, that navy was instrumental in its conquest in the Mediterranean, even if it lacked the prestige of the legions or was deemed “un-Roman”. And of course, it relied on naval power and transport for its conquests and territory beyond continental Europe in Africa, Asia, and Britain.

You could argue that there’s an enduring opposition between maritime empires or sea power and territorial empires or land power in modern history, best symbolized by the opposition of the Anglophone naval powers to continental Eurasian powers.

I also have a pet theory that states whose primary military instrument is naval power, particularly those in islands or continents similarly protected by sea, lend themselves less to authoritarian despotism, particularly as they rely less on standing armies or mobilization on a large scale. Also, that their empires are more strategically selective or limited, at least initially, as they tend to be tied to coastal areas, ports, or naval bases – although sooner or later the temptation to conquer territory inland looms large.

The Greeks, particularly the Athenians, and the Phoenicians are the archetypal maritime empires of classical history, while the Italian city-states, notably the Genoese and Venetians, were the archetypal maritime empires of medieval and early modern history. For that matter, maritime empires are a recurring feature among city states, possibly because at sea they can punch above their weight on land.

And arguably the American empire is the archetypal maritime empire of contemporary history, despite its continental base. As its architect (and prophet) of sea power, Alfred Thayer Mahan, famed for his book The Influence of Sea Power Upon History, would have asserted, given his belief that national greatness was inextricably associated with the sea.

Then there are the more exotic maritime empires or thalassocracies beyond Europe – Srivijaya based in Sumatra and similar states in modern Indonesia, the Chola dynasty in southern India, Brunei, and so on.