This is a story of how a great and powerful civilisation - Mediterranean Islam - which, in the mid-18th century was still regarded by Christian Europe with awe, fear and sometimes admiration, was slowly penetrated and subjugated by the fractious states occupying only the north-west corner of the Great Sea and its hinterlands. It is also a story about a particular regional episode in the development of capitalist imperialism as it emerged from its earliest forms based on trade and finance, to eventually become transformed by the ''industrial revolution'' and the emergence of great and heavily-armed rival European nation states, preying upon older, pre-capitalist empires. Writing of the Mediterranean, the historian Linda Colley remarks that, ''This region is often left out of the history of English and British commercial and imperial endeavour''. Since Colley''s observation the gap has been partially filled by Robert Holland''s, Blue-Water Empire. The British in the Mediterranean Since 1800; but, even this particular work - like the bulk of English language works on European Imperialism written for the general reader - is self-evidently about British imperialism. This is not intended as a criticism. The point I wish to make is that there remains an important gap to be filled (actually, more than one). For in the Mediterranean region the history of imperialism since the mid-18th century is a history of not one but six European powers - Britain, France, Russia, Italy, Austria and Spain - jostling for trade, territory and ultimately, the lands and wealth of those they saw as the existential ''other''.

The only other work which touches on this subject is the elderly classic, The Eastern Question, by M.S. Anderson (1966). However Anderson''s work was essentially a study in international relations: it generally avoids any question of ''imperialism'' and it largely ignores any discussion of the southern shores of the Islamic Mediterranean - Morocco, Algeria, Tunisia, Libya and Egypt. Its focus is mainly upon the relations between Christianity and Islam on the Ottoman Empire''s northern shore. So, this is the first of three ''gaps'' my book is intended to fill. The second ''gap'' I am hoping to fill is that, at the point where my narrative begins, and intermittently thereafter, the ''existential other'' referred to above was nevertheless a neighbor: and not infrequently a business partner, and even a friend and ally. And it is this - along with the longevity of the actual process whereby the Islamic Mediterranean was subjugated - which, makes the history of European imperialism in the Mediterranean quite different from the history of imperialism elsewhere.

Under the Roman Empire the Mediterranean had been mare nostrum (our sea). For centuries both its northern and southern shores constituted a largely harmonious polity sharing the same political structures, social mores and (until the emergence of Christianity) a plethora of equally tolerated religions. All this disappeared with the remarkable Arab conquests of the seventh and eighth centuries. Indeed large parts of the Mediterranean''s northern shore, notably Spain and Sicily, were invaded and conquered by the different Arab Muslim empires of the early Middle Ages. Thereafter the Mediterranean became a veritable ''Sea of Troubles''. The continuous wars between Islam and Christianity across the Mediterranean continued in the sixteenth and seventeenth centuries after the armies of the Turkish Ottoman Empire conquered Egypt in 1517 and that empire''s centre of gravity shifted southwards. And as the various Muslim states of North Africa accepted Ottoman rule between 1519 and 1545 their leaders (together with the independent ''Empire'' of Morocco) imposed their own definition of mare nostrum: henceforth ''our sea'' came to be interpreted as ''the sea of Islam'' access to which was to be granted only by the payment of tribute. But even as the wars between the Muslim and Christian Mediterranean states continued, a fundamental commonality of material interests between the two civilisations insisted on reasserting itself.

Trade had always been an abiding characteristic of the Mediterranean world. As the great French historian Fernand Braudel memorably described, even in the sixteenth and early seventeenth centuries - an age of the most fearsome and brutal conflict between Christians and Muslims - much of which took place upon the Mediterranean sea itself,Merchant vessels sailed across it every day. For it was precisely a characteristic of this singular ''world economy'' . that it bestrode the political and cultural frontiers which each in its own way quartered and differentiated the Mediterranean world. The economy, all-invading, mingling together currencies and commodities, tended to promote unity of a kind in a world where everything else seemed to be conspiring to create clearly-distinguished blocs. Economic ties between Muslim and Christian states in the Mediterranean continued to flourish during the seventeenth and eighteenth centuries So when the emerging capitalist states of Christian Europe began to contemplate the acquisition of territory on the southern and eastern shores of the Mediterranean this Great Sea, and the lands which bordered it, had not only been a ''sea of troubles'' since the early middle ages but had also been a region closely integrated by trade, travel and the circulation of silver money; and one where the two dominant politico-religious identities - Christian Europe and Islam - had ''known each other'' for centuries.