Great civilisations are not murdered. Instead, they take their own lives.

So concluded the historian Arnold Toynbee in his 12-volume magnum opus A Study of History. It was an exploration of the rise and fall of 28 different civilisations.

He was right in some respects: civilisations are often responsible for their own decline. However, their self-destruction is usually assisted.

The Roman Empire, for example, was the victim of many ills including overexpansion, climatic change, environmental degradation and poor leadership. But it was also brought to its knees when Rome was sacked by the Visigoths in 410 and the Vandals in 455.

Collapse is often quick and greatness provides no immunity. The Roman Empire covered 4.4 million sq km (1.9 million sq miles) in 390. Five years later, it had plummeted to 2 million sq km (770,000 sq miles). By 476, the empire’s reach was zero.

Our deep past is marked by recurring failure. As part of my research at the Centre for the Study of Existential Risk at the University of Cambridge, I am attempting to find out why collapse occurs through a historical autopsy. What can the rise and fall of historic civilisations tell us about our own? What are the forces that precipitate or delay a collapse? And do we see similar patterns today?

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The first way to look at past civilisations is to compare their longevity. This can be difficult, because there is no strict definition of civilisation, nor an overarching database of their births and deaths.

In the graphic below, I have compared the lifespan of various civilisations, which I define as a society with agriculture, multiple cities, military dominance in its geographical region and a continuous political structure. Given this definition, all empires are civilisations, but not all civilisations are empires. The data is drawn from two studies on the growth and decline of empires (for 3000-600BC and 600BC-600), and an informal, crowd-sourced survey of ancient civilisations (which I have amended).

Click/pinch to enlarge. Here's the full list of the civilisations displayed above. (Credit: Nigel Hawtin)

Collapse can be defined as a rapid and enduring loss of population, identity and socio-economic complexity. Public services crumble and disorder ensues as government loses control of its monopoly on violence.

Virtually all past civilisations have faced this fate. Some recovered or transformed, such as the Chinese and Egyptian. Other collapses were permanent, as was the case of Easter Island. Sometimes the cities at the epicentre of collapse are revived, as was the case with Rome. In other cases, such as the Mayan ruins, they are left abandoned as a mausoleum for future tourists.

What can this tell us about the future of global modern civilisation? Are the lessons of agrarian empires applicable to our post-18th Century period of industrial capitalism?