As noted in the previous post, the “marginal sea” concept has little utility for geo-historical analysis. More useful is the idea of what might be termed an “enclosed sea,” meaning one whose entrance to the open ocean, or strait, is narrow enough that it could have been controlled by a strong state in the ancient, medieval, and early modern periods. Such enclosed seas are few. If we limit our attention to parts of the world that had states during these times, there are really only four straits that count: the Strait of Gibraltar, separating the Mediterranean from the Atlantic; the Danish straits, separating the Baltic Sea from the open margins of the Atlantic; the Strait of Hormuz separating the Persian Gulf from the Indian Ocean; and the Bab-el-Mandeb, separating the Red Sea from the Indian Ocean. Of these, the 13-kilometers-wide Strait of Gibraltar is the narrowest. The Bab-el-Mandeb, in contrast, is 26 kilometers wide at its narrowest extent, whereas the Strait of Hormuz is 39 kilometers wide at its narrowest extent. The Danish Straits do entail some narrow passages, but there are three of them, and the most important, the Great Belt, is 16 kilometers wide at its narrowest point.
The Mediterranean is not only the most enclosed sea, but is also the largest by far. More significant, it opens up to its own enclosed seas, all of which are connected by even narrower passages. The long and meandering Dardanelles, which links the Mediterranean’s marginal Aegean Sea to the Sea of Marmara, is only 0.75 kilometers wide at its narrowest extent, as is the Bosphorus, which connects the Sea of Marmara to the Black Sea. The Strait of Kerch, which connects the Black Sea to the Sea of Azov, is much wider, 3.1 kilometers at its narrowest extent, but is still significantly narrower than the Strait of Gibraltar.
Such observations lead to an inescapable conclusion: the Black Sea system, including Marmara and Azov, is a unique physical-geographical entity. There is nothing else remotely like it on earth, an oddly unrecognized fact. It is also noteworthy that the Black Sea lies near the center of the segment of the world that includes the other enclosed seas, as can be seen on the maps posted below.
The enclosed nature of the Black Sea system has been geopolitically important during several historical periods. Consider, for example, the situation of Athens during its heyday in the fifth and fourth centuries BCE. After the defeat of the Persian Empire, Athens was eager to secure access to the Black Sea and its many resources. The Delian League that is soon created maintained control over both the Dardanelles and the Bosporus. After its defeat by Sparta in the Peloponnesian War, Athens lost this informal Aegean empire, and thus found itself in a strained situation. It eventually cobbled together a new but less-imperial Second Athenian League, which included cities along the Dardanelles and Bosporus. It was at this time that Black Sea grain became essential for the sustenance of Athens (and several other Greek city states). Securing access to the essential grain supply also entailed maintaining a tight alliance with the culturally hybrid Greco-Scythian Bosporan Kingdom, which sat astride the Strait of Kerch (then called the Cimmerian/Kimmerian Bosporus). Fish supplies from the highly productive Sea of Azov and the rivers that flowed into it were also an important resource for Athens, underscoring the significance of its connection with the long-lived (438 BCE –527 CE) Bosporan Kingdom.
For a fascinating account of this relationship, I recommend Alfonso Moreno’s “Athenian Wheat-Tsars: Black Sea Grain and Elite Culture,” which is found in an important book entitled The Black Sea in Antiquity: Regional and Interregional Economic Exchanges. Moreno highlights the close ties between Athenian elites associated with the school of Isocrates (an extremely important although under-appreciated intellectual and political operative), and the Greco-Scythian elites of the Bosporan Kingdom. His final words are worth quoting:
Two things only were needed to ensure the permanence of this system: the good-will of the Bosporan kings, and Athenian control of the route between [the Cimmerian Bosporus and Athens]. As long as Athenian political leadership could provide this, Athens would be fed and a few of its politicians gain enormous power. If correct, we may have here a very different way of understanding this trade: an oligarchic grain supply sustaining a professedly democratic state.
Although the fifth century BCE is usually considered the golden age of ancient Athens, the fourth century BCE was in many respects a more intellectually vibrant period. To a large extent, the culture that allowed such intellectual flourishing was underwritten by the grain and other resources that flowed in from the Black Sea, which in turn entailed maintaining close relations with the states that controlled the crucial choke points leading from the Aegean Sea to the Sea of Azov.