The History of an Idea


By Hugh Kennedy

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From a preeminent scholar of Islamic history, the authoritative history of caliphates from their beginnings in the 7th century to the modern day

In Caliphate, Islamic historian Hugh Kennedy dissects the idea of the caliphate and its history, and explores how it became used and abused today. Contrary to popular belief, there is no one enduring definition of a caliph; rather, the idea of the caliph has been the subject of constant debate and transformation over time. Kennedy offers a grand history of the caliphate since the beginning of Islam to its modern incarnations. Originating in the tumultuous years following the death of the Mohammad in 632, the caliphate, a politico-religious system, flourished in the great days of the Umayyads of Damascus and the Abbasids of Baghdad. From the seventh-century Orthodox caliphs to the nineteenth-century Ottomans, Kennedy explores the tolerant rule of Umar, recounts the traumatic murder of the caliph Uthman, dubbed a tyrant by many, and revels in the flourishing arts of the golden eras of Abbasid Baghdad and Moorish Andalucí Kennedy also examines the modern fate of the caliphate, unraveling the British political schemes to spur dissent against the Ottomans and the ominous efforts of Islamists, including ISIS, to reinvent the history of the caliphate for their own malevolent political ends.

In exploring and explaining the great variety of caliphs who have ruled throughout the ages, Kennedy challenges the very narrow views of the caliphate propagated by extremist groups today. An authoritative new account of the dynasties of Arab leaders throughout the Islamic Golden Age, Caliphate traces the history-and misappropriations-of one of the world’s most potent political ideas.




ADAM WAS THE first caliph. We know that because we are told so in the Qur’ān (2.28) where God says, in reference to Adam, ‘I am placing a caliph on earth’. The Qur’ān refers to one other caliph by name (38.25) and that is when God tells the biblical King David, ‘We have made you a caliph on earth.’

The office, or perhaps role would be more accurate, has scriptural authority and any ruler might be pleased to follow in succession to these two. But what does the word actually mean? The Arabic root khalafa, from which the Arabic term khalīfa (the origin of the English word caliph) comes, is well known, but like many Arabic words it has a variety of English equivalents. Basically it means to succeed or deputize for a person or, in this case, for Allah. It is used in ordinary administrative and secular contexts with these meanings. But, like many passages in the Qur’ān, its precise meaning here is difficult to determine. It clearly cannot mean successor, since God is eternal and therefore, by definition, cannot have a successor, so it must mean deputy or representative of God on earth. But how were Adam and King David chosen as caliphs when other much revered figures, Moses, Joseph and Jesus for example, were not? And what was their function supposed to be? The Holy Book is completely silent about this. All we can deduce from the Qur’anic references is that God did appoint caliphs on at least two occasions. It was therefore logical that He might appoint others as and when it seemed appropriate.

The term appears to have been used in the time of the Prophet Muhammad. When he left Medina on a military expedition or for any other reason, he would appoint a deputy (khalīfa) for the duration of his absence. We know the names of at least some of these and, curiously, most of them were obscure men who played no part in the later history of the institution and their powers were very limited. Only Uthmān, the third caliph, was among their number, and neither Abū Bakr nor Umar, the first two caliphs, were appointed. Nevertheless, it was perhaps because of this use of the term that the Muslims naturally adopted it at the moment of the Prophet’s (permanent) absence.1

The beginnings of the office can be traced back to the swift-moving events which followed the Prophet’s death in 632. According to the majority (Sunni) opinion, Muhammad had left no explicitly acknowledged successor, although he had asked his old friend and colleague Abū Bakr to lead the prayers in his final days, when he was too ill to do so in person. Muhammad had declared that he was the last of the Prophets, that great line of reformers and preachers which stretched back to Adam and who had all tried, with varying degrees of success, to bring mankind back to the worship of the one true God. After Muhammad, no one could claim the title of Prophet of God without proposing an existential challenge to Muhammad and his community.

Another possibility for succession was ruled out by family considerations. Although Muhammad had had a number of wives and children, only one child survived into adulthood, his daughter Fātima. There was therefore no question of direct hereditary succession in the male line, even if Muhammad and his community had wished that (and there is no evidence that they did).

What happened in the hours and days following Muhammad’s death is not entirely clear, but the basic outlines seem to be generally accepted and the events had a profound and lasting influence on the whole later history of the caliphate. To understand them, and how they were remembered, it is necessary to look at the composition of the Muslim community as it existed in Medina at the time. Muhammad was not himself from Medina but was born and brought up in Mecca, some 200 miles to the south. Although tradition insists that his family was not rich, they were important socially as members of Quraysh, the powerful merchant tribe which dominated the city, and they had a prominent role in providing for the pilgrims who, from before the coming of Islam, came to pay their respects to the Kaba, the cube-shaped building at the centre of the city with the black stone inserted into one of its corners, which had been a place of devotion in pre-Islamic times and still forms the focus of the hajj, or Muslim pilgrimage. To be a member of Quraysh was to be part of a leading class which organized the political affairs of the town and the trading caravans which brought much wealth to the city in its barren and desolate environment. Within the Quraysh, Muhammad was a member of the extended family of the Banū Hāshim. This group included his uncle Abū Tālib, whose son Alī later became Muhammad’s son-in-law when he married his daughter Fātima. It did not, however, include the rich and powerful Umayyad family, also from Quraysh, who dominated much of the trade and political life of the settlement.

When Muhammad’s position in Mecca had become increasingly threatened because of hostile reactions to his preaching, especially from other groups in Quraysh like the Umayyads, he was saved by being invited to the city of Medina, then known as Yathrib, by a group of the inhabitants who wanted an outsider to come and try to judge and reconcile the feuds which had plagued the community. It was in these circumstances that he made his famous journey, his Hijra, to the city which was to be his home, and increasingly his power-base, for the rest of his life. He did not make the journey alone. He was joined by a number of members of Quraysh who were committed enough to follow him into exile. They included Abū Bakr, Umar, Uthmān and Alī. Together with their fellow exiles they were known as the muhājirūn, those who had made the Hijra with the Prophet. They came to form an elite within the nascent Muslim community and the epithet muhājirūn, with its connotations of selfless devotion to the Prophet, is one frequently used by jihadi groups today.

The newcomers settled in Medina alongside the existing inhabitants of the oasis, increasingly known as ansār, or helpers of the Prophet. Again, this is a title which has been accepted with honour by modern militant groups. In general the two groups shared the space and resources of the oasis city with remarkably little open friction, perhaps because of the Prophet’s role as mediator. But the differences still existed, based ultimately on kinship, for the ansār of Medina were certainly not of Qurashi origin. There were perhaps social tensions too. The Quraysh were a widely respected group in Arabia, great merchants who organized caravans of camels to Syria and, less often, to Iraq and Yemen. They were men of the world with wide horizons, accustomed to leadership. The ansār were, by contrast, peasants who made their living from tilling the soil and harvesting dates and whose horizons were limited to their own small community. There can be no doubt that many of the Qurashi muhājirūn believed that power and authority naturally belonged to them.

When news spread through the town that Muhammad had died, both parties took action to secure their positions. The ansār gathered together under the portico of one of their houses, which was known as the Saqīfa (Portico) of the Banū Sāida, which was the name of the family who owned the house. Here some of them argued that, with Muhammad gone, his unique authority should be divided, and they should choose one leader while the muhājirūn should choose one of their own. At a crucial moment, a group of muhājirūn burst in on this meeting and demanded that everyone, muhājirūn and ansār alike, should swear allegiance to one of their number, the veteran Abū Bakr, an old man generally venerated by all for his wisdom and his close association with Muhammad. They all took an oath of loyalty to the new leader, an oath known in Arabic as a baya and symbolized by a stroking or laying on of hands.

There was one small group, however, who did not participate in this agreement. The immediate family of Muhammad was busy, as custom demanded, in washing the body prior to burial. Among them was of course his cousin and son-in-law Alī. He was excluded from the agreement, and though most sources insist that he later accepted it his followers, and perhaps Alī himself, saw this as a coup d’état which had essentially deprived him of his natural rights.

We can never know exactly what happened at the Saqīfa of the Banū Sāida, but it had momentous consequences for future leadership in the Muslim community in a way that none of those present can possibly have imagined. What had begun as an ad hoc response to a temporary crisis became a deciding point whose nature and import were hotly debated for the next fourteen centuries.

Two fundamental issues were at stake here. The first was that the principle was established that the leader of the community, let us call him caliph though the title itself may not have been decided at this early stage, was to be a member of Quraysh. Not everyone agreed, as we shall see when discussing the Kharijites, but most Muslims did and it remains a key doctrine shared by Sunnis and Shiis alike. The other outcome was much more contentious: Alī and the Family of the Prophet more generally had been excluded from the process, denied any opportunity of claiming their rights to succession or expressing their opinions. Furthermore, the ansār, despite all their loyalty to the Prophet, a loyalty which had enabled him to establish his community in Medina and defended him against the onslaughts of the Quraysh of Mecca, were relegated to a second-class status. In the long history of the caliphate, no claimant has ever emerged to demand the title on the grounds of his descent from the ansār. It is impossible to understand the divisions within the Muslim community about the nature of caliphate without understanding what happened, or much more importantly, what was believed to have happened in the Saqīfa of the Banū Sāida.

According to the later historical narrative, Abū Bakr was accepted by the Muslim community with the title of caliph and this has been the view generally held ever since. In fact, as we have seen, this is not certain and there is some suggestion that Umar was the first man to take the title.2 Whatever the true position, the title was well recognized as that borne by the leader of the Muslim community within a decade of the Prophet’s death.

But what did the early Muslims understand by it? None of the sources spell this out. No one at this early stage explained exactly what they had in mind in writing. Instead we have to deduce and infer from the evidence presented in the reports we find in later chronicles, records of public discussions, always polemical, letters and poetry. Of these, the poetry is in some ways the most valuable. This is because it probably adheres most closely to the usages of the time. While it is possible to edit both narratives and letters to reflect later language, it is hard to do so within the strict and formal metres of classical Arabic poetry without doing obvious violence to the text. Even so, most of the poetry on which we rely dates from the later Umayyad period rather than the very early years.

There was an important uncertainty in the use of the term caliph. Khalīfa, as has already been pointed out, can mean either deputy or successor: but which was it? And who was the caliph deputy or successor of? Two views emerge in early Muslim debates on this issue. One is that it means the deputy of God—we often find the phrase ‘deputy of God on his earth’ (khalīfat Allah fi ardihi). There is no ambiguity here because, as we have seen, God cannot have a successor. Some people, however, disagreed, arguing that the full title was always, and should be, ‘successor of the Messenger of God’ (khalīfat rasūl Allah), which must mean successor of Muhammad. This difference mattered, and still does. If the caliph was deputy of God he had a quasi-divine status and authority which all Muslims should support and respect. If, on the other hand, he was simply the successor to Muhammad, that carried much less weight. He could not be a prophet, since Muhammad had been the last of those, so he must be an ordinary man who fulfilled some of the secular and administrative functions that the Messenger of God had performed in his lifetime.

Among both Muslims and western scholars the general assumption was that the real title was, and always had been, successor of the Prophet of God. In 1986, however, two scholars of the Islamic Middle East at Cambridge, Patricia Crone and Martin Hinds, published a short but very important book in which they convincingly demonstrated, from a whole variety of textual and numismatic evidence, that the title meant deputy of God from the beginning. The idea that it meant successor, they argue, was introduced by ninth-century ulama (religious scholars) as an attempt to downgrade the office in the great struggle between caliphs and scholars of that time to control the making of law and the establishment of Islamic norms.3

Caliph was not the only title used for the first leaders. From very early on we have references to the caliph as Amīr al-Mu’minīn, usually translated as Commander of the Faithful. Amīr (often emir in English) means commander or prince. It was a title often given to military leaders and local rulers in the years which followed the break-up of the Abbasid caliphate at the beginning of the tenth century and is still used as a royal title today in the Gulf States. The Mu’minīn element is more problematic: would it not have been much more logical and appropriate to use the word Muslims and describe the leader as Amīr al-Muslimīn? Mu’minīn, however, could be used to describe not just Muslims but also non-Muslims who had entered into a binding peace agreement with them. Unlike the word caliph, the title of Commander of the Faithful does not appear in the Qur’ān so we can find no guidance there, but the use of the term in later texts suggests that it was used very early on and dates from a time when the Muslims fought alongside non-Muslim allies. Whatever its origins and original implications, the title became inextricably linked to that of caliph: not just Umayyads and Abbasids but Fatimids and Almohads and many other rulers who claimed the caliphal title also described themselves as Commanders of the Faithful.

We also find the use of the title imam. Imam means essentially anyone who stands in front or leads. It often describes the prayer leader in a mosque. It is also used, especially among the Shia, to describe the ruler of the whole Muslim community and, as such, is often a synonym for caliph.


The first four caliphs, Abū Bakr (632–4), Umar b. al-Khattāb (634–44), Uthmān b. Affān (644–56) and Alī b. Abī Tālib (656–61), are described in the Arabic sources as Rāshidūn, usually translated into English as ‘Orthodox’. This is a usage dating from the time when most Sunni Muslims could agree that these four were righteous and God-guided rulers, even if things had started to go wrong under their Umayyad and later successors. The term serves as a convenient and widely accepted way of designating the four unrelated and very different rulers.

The historical sources provide a huge variety of information about the four men because the events of these early years had significant and lasting consequences for the development of the Islamic community: crucially, they laid the basis of the division between Sunni and Shiite Muslims, which was to grow in the next four centuries. In the Sunni tradition, they emerge as very distinctive personalities: Abū Bakr the dignified and affable old man, Umar the organizer and stern moralist, Uthmān a good man fatally flawed by his predilection for his own family, and Alī a true ruler but vacillating and overwhelmed by events. These characteristics probably do reflect their real personalities, but they also serve to make points about the nature of caliphal government and later ages looked back to the first caliphs’ reigns as examples of both good government and how things could go wrong. The Orthodox caliphs figure prominently in modern discussions about the caliphate.

All four had important issues to tackle. The first was to secure the continued existence of the Islamic community after the death of its founder and establish the position of its ruler. In the time of Umar, the most obvious priority was managing the great Arab conquests of the Middle East initiated under Abū Bakr and continued through Umar’s reign. By the time of his death in 644, Muslims armies had conquered Syria, Iraq and Egypt, and in the first half of Uthmān’s reign most of Iran and large swathes of North Africa had been added to the list. It was the caliphs, from their capital in the Prophet’s city of Medina, who organized and dispatched the armies which brought down the great East Roman and Persian empires, though none of the caliphs led the Muslim armies in person.

Conquest did not mean that all the peoples of these areas became Muslim: it simply meant that they were forced to accept the political authority of the new Arab-Muslim ruling class. The conversion of the majority of populations to Islam was a much slower and more peaceful process, which probably took four or five centuries. It was a great achievement, which completely reshaped the ancient world and whose consequences are still very much with us today. Organizing the armies was, in a sense, the easy bit. More problematic was the administration of these rich and varied areas once they had come under Arab-Muslim control. And the most complex task was managing the Muslim elite and trying to keep the fierce rivalries which developed from splitting the Muslim world apart.

As soon as he became leader in 632, Abū Bakr was confronted with a major challenge. In the last two years of his life, the Prophet had attracted followers from all over the Arabian Peninsula. They came in delegations to pledge allegiance to him as the Messenger of God and as leader of an increasingly powerful tribal federation with whom it was important to keep on good terms. They often agreed to pay an alms tax (sadaqa or zakat). With the Prophet’s death many of them repudiated the agreements made, arguing that they had pledged allegiance to Muhammad in person, not to his successors or the community in Medina. Others said that they wanted to continue to be Muslims but not to pay the tax. Yet others chose prophets of their own, like Musaylima in eastern Arabia, arguing that if Quraysh had a prophet, then it was only fair that they should have one too. In the Muslim tradition this movement was known as the ridda, or rejection.

Such a moment could have seen the break-up of the umma and a return to the fragmentation and anarchy which had characterized Arabia before the coming of Islam. However, Abū Bakr, ably supported by Umar, decided that this was not to be and initiated a series of military campaigns, often led by Khālid b. al-Walīd, a member of the old aristocracy of Quraysh and later venerated in history and legend as the ‘Sword of Islam’. The campaigns were pursued without mercy and were swiftly successful. By the end of Abū Bakr’s short reign in 634, the tribes of Arabia were effectively brought back under the control of Medina. In doing so, Abū Bakr and Umar had established a new principle: there was no going back on acceptance of Islam. The rejectionist, or apostate (Arabic murtadd), could and should be killed by any righteous Muslim. The ridda also led to the emergence of a new class of Muslims. If the muhājirūn and Quraysh more generally were the elite of the community with the ansār in a subordinate but still important position, the rejectionists who had been brought back to the community in the wars were third-class citizens. This became significant later with the division of assets and spoils which followed the great Arab conquests.

Abū Bakr died peacefully in his old age. In his two-year reign he had accomplished a great deal. There is no explicit evidence that he ever held the title of caliph, but early Muslims certainly believed he had and his achievements and reputation meant that the office became established among them. He also acquired among writers and poets of the Umayyad period and later the informal title of Siddīq, the Truthful or Trustworthy, reflecting the respect in which his memory was held by most Muslims.

The great Arab conquests were essentially a continuation of the wars against the rejectionists. This is not the place to rehearse the details of the various campaigns and battles, but a few aspects should be noted. Initially, from around 634, there were two main fronts, Syria and Iraq. Syria had been the object of the first tentative expeditions at the end of the Prophet’s life. This was pursued after his death, and the conquest of Syria was achieved by comparatively small numbers of members of the Muslim elite and tribes from the Hijaz in western Arabia, sometimes in alliance with other tribes already established in Syria, some of whom were, and continued to be, Christians. It was they who defeated the Byzantine armies at the Battle of Yarmuk in 636 and brought to an end 1,000 years of rule by Greek-speaking elites in Syria and Palestine. In contrast, Iraq was conquered in the main by larger numbers of tribesmen from northern and eastern Arabia and as far south as Oman. The leadership of the campaigns was mostly entrusted to members of Quraysh such as Sad b. Abī Waqqās, who commanded the army which defeated the Persians at the decisive Battle of Qādisiyya, also in 636, and drove them out of Iraq. But most of the rank and file of the army came from non-elite groups and, in some cases, from those who had originally joined the rejectionists. This was to lead to continuous and sustained conflict between Iraqi and Syrian Arab Muslims, a conflict which ultimately led to the end of the Orthodox caliphate.

Another significant aspect of these conquests is that they were organized military expeditions. They were not a mass migration of barbarian tribesmen into a rich and civilized Middle East but armies recruited from volunteers who came to Medina and were assigned to various commanders and sent off in different directions. The overall management of this enterprise fell to the caliphs, above all Umar, who in the ten years of his rule masterminded the most important military operations.

The expeditions of conquest succeeded on a scale which must have been beyond the expectations of even the most optimistic of the early Muslims. In a few short years they had come to control large areas of territory and a numerous population in towns and villages, hamlets and farms, a desirable but unfamiliar resource base. How then were these lands to be administered and how were Muslims to be justly rewarded for their part in the victorious campaigns? At first, especially in Iraq, there was something of a free-for-all as individual commanders tried to seize estates and lands themselves. Umar, however soon put a stop to this and it is a measure of the authority and prestige already enjoyed by the caliph that he was able to do so.

Instead, he instituted a system in Iraq in which the conquered lands and the revenues which could be collected from them were kept as an undivided resource (fay is the Arabic word), the proceeds of which should be used to support the Arab tribesmen. These were not to be allowed to spread out throughout the conquered territory but were settled in specially founded new towns (Ar. misr, pl. amsār). The first of them were Kufa in central Iraq, south of modern Baghdad, and Basra at the head of the Gulf. They were followed by Fustat (Old Cairo) and Qayrawan in Tunisia, Mosul in northern Iraq and Shiraz in south-western Iran. Their names and the payments to which they were entitled were written in lists called dīwāns. None of these have survived in their original form, but their existence shows that firm government control had been established over the movements and settlements of the Arabs.

The new arrangements instituted by Umar had a profound and lasting effect on Muslim society. Much of this was positive. The presence of large numbers of soldiers, dependent on salaries paid by the government, was a major factor in the emergence of that vibrant market economy characteristic of the early Islamic world. It also meant that the government had to use coins and maintain a bureaucracy which was both literate and numerate. This in turn led to the development of a class educated in Arabic with the opportunity and knowledge to invest in writing and other intellectual activities.

At the same time, however, the arrangements gave rise to continuous conflicts over the distribution of resources. These arose at different levels. Within communities, they developed between early converts to Islam, who enjoyed precedence (sābiqa) and hence higher salaries, and later joiners and former rejectionists, who were on very low levels of reward. Then there were conflicts between those who believed that all the money raised in a province, say Kufa for example, should be spent in that province and those who argued that the surplus after paying salaries should be forwarded to the government of the caliph in Medina or, under the Umayyads, Damascus. The fact that the system had been inaugurated by the caliph Umar, as was later confirmed by Alī, gave it a quasi-religious authority. Those who believed that they had a right to all the tax revenues of the province, which should be distributed in the ways laid down by Umar, saw this not just as their earthly rights (dunya) but as part and parcel of their religious faith (dīn), and when the Umayyads tried to change the arrangements in the interests of more efficient government they were seen not only as mean and grasping, but as impious and anti-Islamic.

Another lasting legacy for which the caliph is remembered is the so-called ‘pact of Umar’. This is not so much a written document drawn up and signed by the caliph as a series of rules and guidelines which emerged concerning the status of his non-Muslim subjects, Jews, Christians, Zoroastrians and others. The basic outline of these agreements were that non-Muslims would be able to retain their faith, their worship and their places of worship, along with their personal property and


  • "The doctrine of the caliphate still animates the imagination of Muslim theologians, politicians and ideologues, as Hugh Kennedy shows powerfully in Caliphate."—Wall Street Journal
  • "Hugh Kennedy demonstrates in Caliphate: The History of an Idea, his readable but scholarly account, [the caliphate] was present throughout centuries of Muslim history, in a variety of guises."
    New York Review of Books
  • "[A] sweeping, yet deeply researched, history of popular and scholarly efforts-from the mid-seventh century to the present day....extraordinarily important..."
  • "British historian Hugh Kennedy takes it upon himself to recover the caliphate's meaning, and he succeeds with welcome doses of erudition, accuracy and, when necessary, empathy."—Washington Post
  • "An engaging portrait of a fascinating, multifaceted history."—Times Literary Supplement
  • "[An] engrossing and entertaining introduction... Kennedy clearly shows the continuing power of this idea to incite controversy."—Publishers Weekly
  • "Enlisting significant Arab-language scholarship, Kennedy provides a carefully calibrated, timely chronicle for nonacademic readers."—Kirkus Reviews

On Sale
Oct 11, 2016
Page Count
336 pages
Basic Books

Hugh Kennedy

About the Author

Hugh Kennedy is a professor of Arabic at SOAS, University of London. The author of many books, including The Courts of the Caliphs and The Great Arab Conquests, Kennedy lives in London and Scotland, Great Britain.

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