The most celebrated work of historical writing in English, if one sets aside Sellar and Yeatman's 1066 and All That,Footnote ¹ is probably Edward Gibbon's The History of the Decline and Fall of the Roman Empire. Like many classics, it perhaps has obeisance paid to it more often than it is actually read. Some years ago I gave a paper in London on Gibbon,Footnote ² in the course of which I asked how many of my audience had read the book right through. Four distinguished professors emeriti raised their hands. The younger generation, it would seem, did not spend its time ploughing through lengthy volumes of eighteenth-century prose.Footnote ³ This, however, did not necessarily mean that Gibbon's influence had vanished. I suggest that the mere title of Gibbon's famous book,Footnote ⁴ or at best a misunderstanding of him based on a tendency to stop reading him half-way through, may have contributed to forming our underlying attitudes towards the end of empires. One could formulate it as Gibbon's Law: “Empires may not fall until they have previously undergone a process of decline”. It may be that this has mesmerised historians into expecting, and thus inevitably finding, the ‘decline and fall’ sequence.

This is not to suggest that, even in the Roman case, there has been no questioning of the ‘decline and fall’ paradigm. There is, to put it mildly, no shortage of explanations for the fall of Rome. Dr Bryan Ward-Perkins reproduces a list (in German) of 210 reasons which have at one time or another been advanced.Footnote ⁵ Professor Peter Brown, reviewing Ramsay MacMullen's Roman Social Relations, remarks that “Professor MacMullen's classical Roman Empire of the first and second centuries – a society where wealth has already drained into the hands of the few, whose countryside was ravaged by endemic violence, whose population lived on the brink of famine – is not the sort of empire to have a straightforward ‘Decline and Fall’. For it could hardly have declined much further”.Footnote ⁶

Indeed, the dominant way during the last thirty years of looking at those centuries – between around AD 250 and 750, say – has been to see them not as “the end of the ancient world” or “the beginning of the Middle Ages”, but as a period in its own right, with its own positive character. As Ward-Perkins remarks, “the intellectual guru of this movement is a brilliant historian and stylist, Peter Brown, who published in 1971 The World of Late Antiquity. In it he defined a new period, ‘Late Antiquity’, beginning in around AD 200 and lasting right up to the eighth century, characterised, not by the dissolution of half the Roman empire, but by vibrant religious and cultural debate”.Footnote ⁷ What is particularly interesting about Ward-Perkins's book is that it is an open challenge to this emergent orthodoxy. For him, things were indeed awful, as portrayed in the older tradition. Rome did fall, and being around at the time was no joke. Yet even Ward-Perkins does not seem to believe in a long drawn-out ‘decline’ preceding the fifth-century ‘fall’. For him, the Western Roman Empire was still very formidable indeed as it entered that century.

Virtually simultaneously with Ward-Perkins, another Late Antique historian published his own examination of the same problem. This was Professor Peter Heather. His book is very different from Ward-Perkins's. It is much longer, and it concentrates far more, as its subtitle indicates, on the subject of much of Heather's earlier research: the barbarians.Footnote ⁸ It is worth quoting some of Heather's conclusion: “The Roman Empire had sown the seeds of its own destruction . . . not because of internal weaknesses that had evolved over the centuries, nor because of new ones evolved, but as a consequence of its relationship with the Germanic world . . . The west Roman state fell not because of the weight of its own ‘stupendous fabric’, but because its Germanic neighbours had responded to its power in ways that the Romans could never have foreseen”.Footnote ⁹ Again, then, we have nothing that much resembles a traditional ‘decline and fall’.

What, if anything, is the relevance of all this to the study of the end of the Mongol Empire? I suggest that we should approach that phenomenon – or rather that series of phenomena – with an open mind, and without expecting, necessarily, that we shall find a Gibbonian sequence awaiting our examination. There is an important preliminary question: are we talking about the break-up of the Mongol Empire, or about its fall? Are these, in fact, two quite different things? In 1978, Professor Peter Jackson published what proved a deservedly influential article on “The dissolution of the Mongol Empire”.Footnote ¹⁰ I was (and still am) inclined to disagree with some of the details of his argument, but its essential message was clearly right: the Mongol Empire ‘dissolved’ around the year 1260, that is, not much more than thirty years after the death of its founder, Chinggis Khan; and, paradoxically, twenty years before it reached its greatest geographical extent after the definitive conquest of the Song Empire in south China.

This did not of course mean that the Mongol Empire disappeared, or even that it began to fade away. One of the most obvious ways in which that empire was different from what one might call the normal run of nomad empires is that, far from beginning to contract or even collapse after the death of its charismatic founder, it continued to expand for a further half century, and by 1279 was something like twice as extensive as the already vast realm left by Chinggis Khan at his death in 1227. What Jackson was discussing was the end of the Mongol Empire as any kind of unitary state ruled from a central capital by a paramount emperor and his governmental machine. That, insofar as it can be said to have existed before 1260, certainly came to an end at around that date. There was still a Great Khan – after the civil war of 1260–64 and until his death in 1294 that throne was occupied by Qubilai. But Qubilai's writ, unlike that of his predecessors Chinggis (to 1227), Ögedei (1229–41), Güyük (1246–8) and Möngke (1251–9), did not run the length and breadth of the Mongol Empire: nor did anyone else's. He was recognised, indeed with some enthusiasm, by his close relatives the Ilkhans of Persia, but that was about it. The Mongol Empire, if one may be permitted to oversimplify a little, was now divided into four more or less independent khanates, ruled by different branches of the Mongol royal house that descended from Chinggis Khan. The Great Khan ruled in China and Mongolia, the descendants of his brother Hülegü ruled the Ilkhanate in Persia, Iraq and much of Anatolia, the hostile descendants of Chinggis's eldest son Jochi ruled the Golden Horde in the Pontic steppes, and in theory the descendants of Chinggis's second son Chaghatai, also hostile to Qubilai, ruled in Central Asia (although in fact the paramount power in the lands of the Chaghatai Khanate, until his death in 1303, was Qaidu, a descendant of Chinggis's third son and successor ÖgedeiFootnote ¹¹).

Why did this happen? The various enmities that proliferated within the royal house were no doubt the result of particular circumstances. For example, the Golden Horde ruler Berke was at odds with his cousin Hülegü perhaps because, being himself a convert to Islam, he was less than enthused by Hülegü's execution of the last ‘Abbasid caliph of Baghdad in 1258. More certainly, he undoubtedly took the view that what he considered the Golden Horde's territorial rights in the Caucasus had been usurped by the newly-established Ilkhanate. There were many such causes of conflict, potential and actual, between members of the ‘golden family’. But the principal underlying reason for the ‘dissolution’ of the Mongol Empire is surely one of simple practicality. In the long run, and in thirteenth-century conditions, it was not possible to run so vast an empire as a centrally-directed polity. Some kind of devolution was inevitable. But perhaps it could have been an amicable division of authority, which need not have resulted in internecine warfare. Indeed, under Qubilai's successor as Great Khan, Temür Öljeitü (1294–1307), some such arrangement does seem, for a time, to have been arrived at.

But in 1260 that was a long way in the future. The fact of the matter is that after the coup d'état of 1251, in which Möngke became Great Khan, with the help of Batu of the Golden Horde and at the price of a purge of the houses of Ögedei and Chaghatai, and after the disputed election to the Great Khanate in 1260, there was little chance that the high politics of the Mongol Empire would be sorted out by consensus among the members of its ruling family, as had been the original conception of the function of the quriltai, the assembly of princes and notables. Instead, what became dominant was the principle which the late Professor Joseph Fletcher, borrowing somewhat freely from Celtic society, called ‘tanistry’. According to this, the member of the ruling house who should hold power was the one most fitted to do so; a conundrum most likely to be solved by acknowledging the one who came out on top during a violent struggle for the succession and who had thus demonstrated his suitability.

Perhaps more ominous than sanguinary feuding between Chinggisid cousins was another consequence of the warfare between the Golden Horde and the Ilkhanate in the 1260s: the alliance which developed, and endured, between the Golden Horde and the Mamluk sultanate of Egypt and Syria. Here what transpired was that a Mongol regime was prepared to ally itself with a non-Mongol regime, against its fellow-Mongols of the Ilkhanate. It was henceforth difficult to pretend that a united Mongol people was any longer pressing forward to the common ultimate goal, realisation of the Eternal Blue Heaven's decree that the world and the Mongol Empire were coterminous. That commercial considerations underlay the alliance – the territories of the Golden Horde were the main recruiting grounds for the mamluks, the military slaves, on which the Egyptian regime depended – was significant but did not alter the ideological shift that the alliance implied. For all that south China had yet to be conquered in the 1260s, the irresistible expansion of Mongol power which had been the world's major political fact for half a century was now, evidently, grinding to a halt. The Mongols of the Ilkhanate would continue to invade Syria for several decades. The Mongols of the Golden Horde would continue to raid in Eastern Europe; so would the Chaghatais into India. But Egypt and North Africa, Western Europe and India would not now become provinces of the Mongol Empire (even if much of India ultimately became a Mongol, or Mughal, Empire in its own right).

It would be possible to argue that the end of expansion in the case of a conquest empire like that of the Mongols, predicated as it originally was on an endless supply of booty, constitutes a decline. Certainly it necessitated a shift in emphasis, at least in some parts of the empire, away from plunder and towards more or less regular taxation. My own suspicion about the numerous Ilkhanid incursions into Syria after 1260 is that they were more a way of keeping the brutal and licentious Mongol soldiery contented and supplied with loot than serious attempts at permanently expanding the imperial frontiers. The trouble with nomadic tribal cavalrymen is that if they do not have an external enemy to keep them occupied, they are liable to start breaking up the furniture at home.Footnote ¹²

This brings us to the point where some important distinctions have to be made between the various constituent khanates of the post-1260 Mongol Empire. Movement away from a conquest- and raid-based empire of plunder was inevitably much more pronounced in the essentially sedentary parts of the Mongol realms than in the more nomadic areas. The Toluid khanates, those ruled by the descendants of Chinggis Khan's youngest son Tolui, were as it happened the most thoroughly sedentary territories. The Toluids ruled in China and Mongolia (Mongolia was of course mainly nomadic, but it was sedentary China that really mattered); and in Persia. Persia contains lands that are suitable for nomadic herding but not for agriculture; but this was, nevertheless, basically a sedentary society. The Golden Horde and the Chaghatai Khanate, on the other hand, were essentially nomadic. Now it so happens that Mongol rule collapsed first in Persia, then in China. It survived for far longer in the lands of the Golden Horde and Chaghatai. Should this be taken to be coincidence?

I strongly suspect not. Recent work on the history of the Mongol Empire has tended to stress the positive aspects of Mongol rule – for example the constructive, active and fertile role played by the Mongols in many varieties of cultural transmission across Eurasia.Footnote ¹³ This is an entirely justifiable emphasis, and a most necessary corrective to a traditional image of the Mongol period which portrays it as consisting of little more than death and destruction on a massive scale. But that should not blind us to the fact that, in the last analysis, Mongol rule depended on Mongol military supremacy: on an ability to keep internal order and to fend off external attack. Not that external attack was usually the main problem: as we shall see, it is not for the most part possible to ascribe the fall of the Mongol Empire, as it has often been argued is valid in the Roman case, to military pressure and ultimate conquest by external military forces. Most of the Mongols’ problems were internal in origin. So it was above all the maintenance of internal order, a sufficiently functioning government and in particular an adequate income from taxation revenue, that mattered most. All of these were dependent on the government's continuing to possess overwhelming military supremacy. And that was something that was far easier to sustain in the more traditionally nomadic areas.

It should not be forgotten what it was that made the Mongols, and other Central Asian steppe warriors like them, so formidable. A competently led and adequately armed force of Central Asian cavalry archers was, other things being equal, unsurpassable on the field of battle (however useless it might be in siege warfare), until the development of efficient battlefield artillery and handguns. This was a very long time indeed after the invention of gunpowder (or its transmission to Europe under perhaps unwitting Mongol auspices, as some scholars believe). It would be centuries before any handgun could match the composite bow of the steppe in any quality that mattered, whether range, accuracy, rate of fire or power of penetration.Footnote ¹⁴ But what made the individual steppe archer so formidable was that his whole way of life was a training for warfare. The same tactics that were used in hunting and herding were easily and effectively adapted to warfare. This facility was something which could well be lost if the troopers on whose military capacities the regime depended began to settle down. And, to a greater or lesser extent, the Mongols in Persia and China do indeed seem to have done their best to settle down. Rashid al-Din, the great Ilkhanid bureaucrat and historian, tells us that towards the end of the reign of the reforming Ghazan Khan (r.1295–1304), the monarch proposed to pay his troops by issuing them with iqtas, assignments of land, and he asserts that “at this time, most of the soldiers had the desire for estates (amlak) and for the (practice of) agriculture”.Footnote ¹⁵ That was no way to preserve the Good Old Days and Mongol military superiority. And in intensely agricultural China the maintenance of a nomadic lifestyle will have been a great deal more difficult than it was in Persia.

Let us, then, look at what happened to bring Mongol rule to an end in the four main subdivisions of the Mongol Empire.

The Ilkhanate has long been my locus classicus of the problems inherent in ‘Gibbon's Law’. For all the difficulties which the Ilkhans’ relatives in the Golden Horde and the Chaghatai Khanate may have caused them, there was never any serious danger that the llkhanate would be destroyed as a consequence of external attack. How one views the rule of the Ilkhans can vary a good deal. Traditionally the pattern has been seen as one in which the early Ilkhans were incompetent and oppressive tyrants who created a dreadful mess which had to be cleared up by the great reformer (and first of the line of Muslim Ilkhans) Ghazan Khan. That is more or less the view one would have if one got one's history predominantly from Rashid al-Din, which is what most of us have tended to do. Recently, Dr George Lane has argued that the early Ilkhans were in fact vastly more enlightened rulers than has been supposed.Footnote ¹⁶ On a rather different tack, Professor Charles Melville has suggested – very plausibly, to my mind – that the Mongols of the Ilkhanate might well not have shared our (and Rashid al-Din's) view of what was desirable in a regime. They may have seen the reign of Ghazan as the thoroughly unwelcome end of the Good Old Days.Footnote ¹⁷

Either way, so far as the issue of ‘decline and fall’ is concerned, much depends on what one makes of the reign of the last of the uninterrupted line of Ilkhans descended from Hülegü, Abu Sa'id (1316–35).Footnote ¹⁸ For it was after his death that Ilkhanid rule collapsed. Why? Melville considers it all explicable in terms of long-term decay, factional struggle and disintegration. His examination of the period,Footnote ¹⁹ based in part on sources which have never before been seriously exploited, is far more detailed than anything previously available to us. Yet I have to say that I am not convinced that the reign of Abu Sa'id was qualitatively that much worse than many previous periods in Ilkhanid history; and I wonder whether any impression that it was may have something to do with the lower quality of the historical sources available for the study of this final period.

I have become mildly notorious for maintaining that the Ilkhanate, in barefaced defiance of ‘Gibbon's Law’, fell without having previously declined: even Melville has found me useful in this respect as a kind of straw man. In my book, The Mongols, I wondered if some significance could be attached to what was alleged to have been a decline in the quality of the coinage during Abu Sa'id's reign.Footnote ²⁰ But in what was in my opinion much the most interesting review the book received, Professor John Masson Smith Jr. commented that “these coins did not degenerate. The weight of the silver coin was somewhat reduced on three occasions, perhaps to keep newly-issued coins at about the same weight as older coins worn in circulation, but similar reductions had previously been made by Abaqa, Ghazan and Öljeitü, before the ‘decline’. Otherwise, Abu Sa'id's silver coinage was as pure as ever, artistically superior to all other Mongol – and most other Islamic – coinage, and much more voluminous than that of preceding reigns; monetarily (and actually, in my opinion) the Mongols of the Middle East reached the height of their powers under Abu Sa'id”.Footnote ²¹

What had broken down in the Ilkhanate was the consensus, or any general agreement on how a consensus should be arrived at, about the succession to the throne. Abu Sa'id's problem was much the same as Henry VIII of England's: his difficulty in providing a male heir. Henry managed it in the end, after a fashion. Abu Sa'id did not, and there was therefore no unchallengeable member of the line of Hülegü available to succeed him when he died in 1335. Various expedients were tried by several factions. But essentially the throne was up for grabs, and the central government disintegrated as a result. Parts of the khanate fell under the control of what would now probably be called warlords – some Mongol, some not. No one had general control or widespread acknowledgement of legitimacy. Such was the situation until Mongol rule of a sort was reimposed towards the end of the century by Tamerlane, who though Turkish in speech was Mongol by descent (albeit hailing from a different Mongol realm, the Chaghatai Khanate), and who does appear to have seen himself as Abu Sa'id's successor. But I do not myself see any compelling reason for supposing that Ilkhanid rule would necessarily have collapsed when it did, or for long after, had the line of Hülegü continued uninterruptedly after the death of Abu Sa'id.

Next came China, the other major – even more so – sedentary area of the Mongol Empire. The Mongols were driven out, back to Mongolia, in 1368. How did that come about?

The last Yuan (Mongol) emperor, Toghon Temür, is an interestingly close parallel with Abu Sa'id, briefly his contemporary. Like him, his reign was the longest of any member of the dynasty (1333–68); and like him, he came to the throne as a child, his reign being destined to be plagued by factional struggles (it was also to be plagued by plague: that, at least, was not a problem with which Abu Sa'id had to deal). The major difference is that Abu Sa'id died still in power: it was his death that precipitated collapse. But Toghon Temür was ejected from his throne, and obliged to flee back to Mongolia, where he died two years later.

There is no doubt that the mid-fourteenth century was a difficult time in many parts of the world. Mongol China suffered as much as anywhere, being afflicted with a variety of natural disasters – especially floods and pestilences. The theory that the Black Death began in China, and travelled to Europe across the Mongol Empire's trade routes, is well known. The Chinese economy was so dependent on the waters of the Yellow and Yangtse rivers that any major disruption could have catastrophic consequences. In this connection it is worth noting that the government of Toghon Temür managed in 1351 to re-route the course of the Yellow River so that it flowed into the sea south of the Shantung peninsula – something for which there was no precedent.Footnote ²² Only seventeen years before its fall, the Mongol government in China could still accomplish remarkable things.

The predominant feature of the final years of Yuan rule, however – if one is looking for evidence of ‘decline’ – is the increasing frequency and seriousness of native Chinese revolts, especially in south China, and a loss of grip on the part of the central government. The Mongol armies were no longer of a quality to be able to deal effectively with these problems. More important, there were not enough of them; and the fourteenth-century neglect and impoverishment of Mongolia itself had meant that few new recruits could be hoped for from the homeland.Footnote ²³ In a passage which has curious echoes of a different place and a more recent time, Professor Dardess writes that “there were never at any time enough regular Yuan troops to handle the nationwide breakdown of order that set China aflame in the early 1350s . . . Yüan military units of every description and national origin were pressed into service, and . . . local defense militias, Chinese armies recruited for the occasion, played a major part in turning back the rebel tide. The rebellions could not have been handled otherwise”.Footnote ²⁴

The dynasty remained important for legitimisation purposes, but its actual power tended to be concentrated more and more in just the area around the capital. In the rest of the country, warlords – whether Mongol or Chinese – ruled, in most cases continuing to profess allegiance to the emperor. However, it does seem that there was a moment when everything appeared to be coming back under control. In 1354 the principal minister, Chancellor of the Right Toghto, took personal command of a major expedition against rebel forces, laying siege to the city of Kao-yu, refuge of the leading rebel Chang Shih-ch'eng. “Had the siege of Kao-yu in fact forced Chang Shi-ch'eng's surrender, which was all but inevitable, the back of the nationwide rebellions would have been resoundingly broken”.Footnote ²⁵ Unfortunately, and for reasons that are by no means clear, the emperor chose that moment to dismiss and banish Toghto, who duly obeyed. The siege disintegrated, and there was never again a similar chance for the government to regain the initiative.

Disintegration is the hallmark of the remaining years of the dynasty, as the rebel groups, particularly the one whose leader was to become the first emperor of the Ming dynasty, gained in strength and seized control of more and more territory. We should note two points: Mongol rule in China fell because of internal collapse, not external attack of any kind; and there was nothing inevitable about what happened. As Professor Paul Buell puts it, “The downfall of the Mongols had come unexpectedly and quickly, just 60 years after the Yuan highpoint under Temür Öljeitü”.Footnote ²⁶ There is every reason to suppose that, handled differently, the government's problems might well have been solved, and Mongol rule continued after 1368.

So much for the ‘sedentary’ sections of the Mongol Empire: what may be said about the more ‘nomadic’ areas, the realms of the Golden Horde and the Chaghatai Khanate?

There is perhaps a sense in which the continued dominance of the nomadic lifestyle in the Chaghatai territories was as much a weakness as a strength. It is certainly true that Chaghatai rule continued in the eastern half of their territories – roughly what is now Chinese Central Asia – for a very long time: indeed, the dynasty did not finally expire until 1678, and for centuries a claim to a Chinggisid lineage was a necessary element of legitimacy for Central Asian rulers. And perhaps the continued emphasis on the Mongols’ traditional lifestyle helped them to survive economic or other difficulties which might have wrecked a sedentarily-based regime, as well as enabling them to retain their military effectiveness. But all this, on the other hand, lost them their control of their richest territories, the western half, Transoxania. By the mid-fourteenth century, a variety of Chaghatai amirs had become the effective holders of power there, and this was the background to the rise of Tamerlane. I cannot deal with that here.Footnote ²⁷ But suffice it to say that although his own background was tribal and nomadic, his solid power base in Transoxania owed a great deal to the way in which the sedentary population saw him as their defender against the predatory Chaghatais from the east. Tamerlane suffered from not being of Chinggisid descent, a problem he tried to deal with in various ways. He does seem to have envisaged his career as one whose purpose was the reconstruction of the Mongol Empire. But however much he may have modelled himself on Chinggis Khan, he was not that kind of empire-builder: once he was dead, his empire began to contract and disintegrate.

The Chaghatai Khanate remains the part of the Mongol Empire about which we know the least, to some extent because of the almost total dearth of indigenous sources on its history. The Golden Horde is not much better in that respect; but at least writers from outside its borders – especially in Mamluk Egypt and in the Rus principalities – showed some interest in what was going on there.

The traditional view of the ‘fall’ of the Golden Horde would go something like this. The direct line of Batu ultimately expired in the course of the fourteenth century, and as Mongol power declined the strength of its former vassals, the Russian princes and especially those of Moscow, grew. The old Golden Horde territories were divided among several successor khanates, with some degree of at least nominal overlordship being granted to what was called the ‘Great Horde’. That came to an end when it was destroyed by an alliance between the Mongol Khan of the Crimea, Mengli Girai, and the Russians, in 1502. That date therefore marks the end of the Golden Horde. True, the Crimean khanate continued – it had accepted some degree of Ottoman suzerainty since 1475 – till it was annexed by Catherine the Great in 1783, but that does not count.

There is a problem with this formulation: a problem exposed, with extraordinary, indeed one might well think somewhat disproportionate, passion, by the late Leslie Collins in a remarkable article.Footnote ²⁸ What Collins attempts, in my opinion successfully, to show is that there is no evidence that anyone at the time saw the events of 1502 as marking the end of the Great Horde. To summarise the conclusion of a long argument, what Collins contends is that Mengli Girai's achievement in 1502 was not to destroy, but to take over, the Great Horde – which had changed hands in similar ways on a number of previous occasions. The Great Horde, then, continued: the only difference was that that paramount Golden Horde throne was henceforth held by the Khan of the Crimea.

The Crimean Tatars were very far indeed from being a negligible power. It is said that there came a point at which it looked as if the Ottoman dynasty might become extinct – the Law of Fratricide could create its own problems, if applied with too much enthusiasm. The proposed solution, if this were to happen – in the end it did not – was to import a sultan from the Crimea, since the Chinggisid line represented there was regarded in Istanbul as the only lineage whose prestige was comparable with that of the Ottomans. As a military power, the Crimeans long remained formidable. Collins, in an earlier article,Footnote ²⁹ showed how the Crimean Tatars were still campaigning successfully in Eastern Europe in the seventeenth century – a classic illustration of how unwise it is to write off the effectiveness of the steppe cavalry archer too early.

The late Enoch Powell famously remarked that all political careers end in failure – and his certainly did. Whether he would have considered this dictum to apply also to empires I do not know. They all come to an end, of course, but the manner of their ending varies greatly. It was widely agreed at the time – and subsequently, at least until recently – that the Ottoman Empire began to decline after, if not indeed during, the reign of Sulayman the Magnificent (1520–66). As Jane Hathaway justly remarks, “Seldom does an empire last for three hundred years, and yet the Ottomans are supposed to have had the luxury of declining for such a lengthy span of time”.Footnote ³⁰ It is even arguable that it is a decline that need not necessarily have ended in ‘fall’ when it did, had the Ottomans not been so injudicious as to choose the wrong side in the First World War, i.e. the side not containing Great Britain. It is customary to argue that the Safavid Empire was in decline for the whole of its second century, after the death of Shah ‘Abbas I. In the relevant volume of the Cambridge History of Iran, this view is duly trotted out by at least two authors, Roger Savory and Laurence Lockhart. But the author of the admirable sequence of chapters on political history, the late Hans Roemer, comments that “this view is emphatically not justified”, or, as he more pithily puts it in the German version of his work, “Zu unrecht!”, which we might perhaps legitimately translate as: “What rot!”.Footnote ³¹ In my view Roemer was right. Historians, I think, have tended to see Persia in the seventeenth century as a society in decline because nothing much actually happened. But it is by no means obvious that this should be taken to imply an adverse judgement on the Safavids: arguably, the opposite. Of course decay did eventually set in, as was demonstrated by the ease with which the Afghans destroyed the Safavid regime in 1722. But there is no need to look back as far as 1629 for its origins: this is a notable example of the dangers of ‘Gibbon's Law’.

One could go on. The late John Richards, the author of the volume on the Mughal Empire in the New Cambridge History of India, once told me that he did not think we should look too far back for signs of Mughal decline. In his opinion the Empire collapsed between 1711 and 1719. I am old enough to remember the extraordinary speed of the British Empire's post-World War II ‘decline and fall’, and it is possible that I shall live to see the same fate befall the American Empire – an eventuality I view with mixed feelings.

What I think the Mongol case demonstrates is that while imperial collapse in one form or another may be inevitable – certainly, so far, it has always happened – there is rarely anything inevitable about the specific circumstances in any particular instance. Parts of the Mongol Empire continued for a very long time; and as it happens those were the parts which retained more of the traditional steppe lifestyle. Other parts collapsed much earlier, and those were the more sedentary areas, where more accommodation to local mores had been necessary, and where less of the nomadic lifestyle had survived. But even in those cases, an examination of the actual events suggests that the Mongol regimes could perfectly well have continued, had different decisions been taken at various points or had different circumstances prevailed. Gibbon may well be the greatest historian ever to have written in English, but in my opinion ‘Gibbon's Law’ does not prove, when one examines specific case histories, to be of much help to the historian. If contemporary historians of the later Roman Empire like Ward-Perkins and Heather have no further use for it, perhaps we too should consign it to that capacious receptacle, the dustbin of history.Footnote ³²