IN Mohammed and Charlemagne – posthumously published in 1937 – renowned historian Henri Pirenne (1862-1935) advanced a thesis at once simple and much contested: that the true rupture between Late Antiquity and the beginning of the Middle Ages was not the fall of Rome in the fifth century, as traditionally held, but the expansion of Islam in the seventh. The Germanic kingdoms, he argued, had preserved much of the Roman economic and cultural architecture. Trade across the Mediterranean continued; cities, though diminished, remained nodes in a wider network sustained by the circulation of goods and by administration. For the Romans, the mare nostrum was a highway rather than a barrier.
If a good article starts after it ends, one might say that a civilisation reveals itself most clearly not in its proclamations, but in the modification of its habits – when what was once assumed becomes contested. In such subtle alterations, Pirenne discerned the end of the ancient world.
With the Islamic expansion the greater part of the Mediterranean’s southern and eastern shores fell under Muslim control, from the Levant and Egypt to North Africa and the Iberian Peninsula. The sea was no longer a unified Roman basin, but a divided one. Authority and function shifted: the Mediterranean ceased to operate as a shared commercial zone. Long-distance trade dwindled, the flow of goods between East and West was disrupted and with it the urban and monetary life that depended upon it. Only then did Western Europe withdraw inward, shrinking into the medieval world as it is recognised today.
The argument has been debated, qualified, and revised. Yet its inner core endures: civilisations are sustained not merely by armies or laws, but by the invisible fibres of exchange – commercial, intellectual and cultural – that bind their parts together. Sever those threads and, without even the cut of a sword, a whole order may vanish into a rumour.
To draw a parallel with present-day Europe is to tread on disputed ground. The language of ‘invasion’ is often employed with more heat than light; yet to deny that significant demographic and cultural changes are under way would be equally unhelpful. The question, then, is whether Pirenne’s model can illuminate what many believe is a tragedy without reducing it to a farce.
The spread of Islam in the seventh and eighth centuries was a series of military conquests. The Arab fleets that took North Africa and Spain, the armies that crossed into Gaul, and the long struggle for control of the Mediterranean were enterprises of war and empire. Contemporary migration into Europe, by contrast, occurs largely through civilian movement, legal and illegal. However, both historical processes demonstrate that massive migratory movements, whatever their specific nature, do not merely add numbers to a population; they introduce new networks, new loyalties, new values and new norms that eventually fracture the existing state of affairs.
Before the eighth century, the Mediterranean economy continues to function, vibrant and connected. After the eighth century, that system is shattered. The sea is closed. Trade disappears. Europe faces an empire whose only wealth is the land, where the movement of goods is reduced to a bare minimum. Far from advancing, society regresses.
Pirenne’s thesis gains thrust and edge in presenting the Islamic expansion as embodying a fundamental alteration in coexistence.
Right at the beginning of the second part of Mohammed and Charlemagne, The Islam and the Carolingians, he writes: ‘Islam means resignation or submission to God, and Muslim signifies one who submits. God is one, and it follows logically that all His servants have the duty to impose Him upon unbelievers, upon infidels. What they aim at is not, as has been said, conversion, but subjection. That is what they bring with them. After conquest, they ask for nothing better than to seize, as spoils, the science and art of the infidels. They will even adopt their institutions insofar as these may prove useful to them. Their own conquests compel them to do so. To govern the empire they have founded, they cannot rely on their tribal institutions, just as the Germans could not impose theirs upon the Roman Empire. The difference lies in this: wherever they are, they dominate. The vanquished become their subjects; they alone pay the tax and remain outside the community of the faithful. The barrier is impassable; no fusion with the conquered populations can occur.’
A stark assertion which leads directly to the present and the tension between those who maintain that continuity is not at risk and those who foresee an unmistakable existential threat and dissolution. Do these new elements integrate into the existing structure, strengthening it, or do they develop in parallel, uneasily alongside it? When Pirenne described the early medieval West, he was portraying a society that had, in effect, lost its connective tissue with the broader Mediterranean world. The risk he identified was not diversity, but disjunction.
The comparison must not be forced beyond its limits. Contemporary mass migration into Europe is a civilian movement, driven by demographic decline that threatens economic growth and the endless reproduction of state bureaucracies determined to preserve their incalculable privileges at all costs.
However, the analogy becomes suggestive. In certain European cities, one observes the emergence of districts where linguistic, cultural, and even legal practices diverge markedly from those of the surrounding community. As these divergences persist they raise questions about the cohesion of the whole. A country can absorb difference but it cannot sustain fragmentation.
The disappearance of papyrus in Western Europe during the seventh and eighth centuries, following the Arab conquest of Egypt, was a telling sign of a deeper rupture: not merely the loss of material, but the collapse of a network of exchange.
What, then, are the modern equivalents of papyrus? Perhaps they are less tangible: the shared assumptions about law, the unspoken norms of public life, the sense – difficult to define but easy to feel – of belonging to a common story. When these begin to fray, the change may go unnoticed until it is well advanced.
This is not history in the abstract. It is a warning: when an incoming population promotes separation, the society it enters is gradually transformed beyond recognition. Civilisation is held together by shared norms, daily habits and the tacit agreement that all belong to the same framework.
Today, Europe faces the same question. The arrival of large populations that operate in many cases outside the existing institutional structures is not a matter of diversity but of parallel worlds forming within the same territory. When newcomers do not share, or are not compelled to share, the rules, the obligations, and the responsibilities of the host nation, cohesion begins to unravel. Pirenne’s lesson is brutal but simple: no civic order can survive when the bonds that hold it together are ignored or replaced. The consequences are profound – and they unfold faster than most realise.
And if a good article begins after it ends, perhaps the true question is not whether Pirenne was right about his own time, but whether we possess the clarity to recognise the shape of ours.
