Segregation in cities: Living in black and white Segregation: A Global History of Divided Cities. By Carl Nightingale. University of Chicago Press; 517 pages; $35 and £22.50. Buy from Amazon.com, Amazon.co.uk CARL NIGHTINGALE'S history of segregation claims to be a detailed account of how cities were, for millennia, divided along racial lines. But it is really a history of how colonialism affected the construction, governance and policing of great urban areas. For the past 500 years white Europeans have often used their economic and military power to build and rebuild urban landscapes in order to grab the safest, healthiest and nicest parts for themselves. Even in places where colonial rule is now a distant memory, many urban environments cannot be understood without recalling their foundation as a fortified enclave for Europeans bent on procuring commodities or opening markets. Calcutta (now Kolkata) was set up in 1690 by a member of Britain's East India Company, in defiance of the local Muslim overlord. It later vied with London as the biggest metropolis in the British empire. Both colonialism itself and the divided cities it spawned reached their zenith on the eve of the first world war. As Europeans migrated in large numbers to far-flung corners of their expanding empires, the need to keep them comfortable, both physically and psychologically, meant that other groups were treated with ever greater ruthlessness. Mr Nightingale shows how the roots of apartheid in South Africa, for example, are to be found much earlier than the 1948 election victory of the National Party; they lie in the colonial project which led to the creation of Johannesburg half a century earlier with white and non-white areas. This was made much more explicit after 1948 - and this shocked a world where racial ideologies and colonialism were being challenged and dismantled. But segregationist zeal did not flare in a vacuum; it built on an existing system of allocating space which reflected the needs of an imperial elite. Those needs were complex and shifting. After their defeat of the Boers in 1902, the British masters of South Africa wanted labour for the gold mines that had given birth to Johannesburg; but they also wanted to attract white, English-speaking immigrants, and to promise them a life in which other races featured only as house servants. Ever more ingenious forms of separation emerged, including the foundation of present-day Soweto beside an urban sewage farm. In Cape Town, a new effort to divide, aimed at keeping Europeans healthy, began after the arrival of bubonic plague at the start of the 20th century. The scourge had been spreading westward from China's ports; in many cities, infectious diseases were the catalysts for grand segregationist projects, and were underpinned by racist ideologies. Mr Nightingale, a professor at the State University of New York in Buffalo, makes a fair case for studying the emergence of colonial cities as a single phenomenon. More contentious is his argument that modern Chicago presents a comparable example of rich white people forcing racial minorities, especially blacks, to live separately and badly. Even when black people were enfranchised and began asserting their civil rights in the 1960s, politics in Chicago was manipulated in ways whose end-result was not so different from apartheid, he argues. One early factor was the emergence of a property market that was distorted by covenants which specified the race of the purchaser. The Supreme Court allowed the practice in 1926, but struck it down in 1948. Later, so-called urban-renewal projects were used to move black communities to less desirable locations, Mr Nightingale says. Poor areas were cleared to build highways that would enable rich commuters to travel more easily between offices and their suburban homes. Mr Nightingale is right to point out that segregation can exist without a formal regime. But he surely underestimates the difference between a country like the United States, where the disadvantaged have legal and political tools at their disposal, and apartheid South Africa where no such tools were available. So powerful is his belief in a handful of "master narratives" that he sometimes shoehorns facts to fit his theories. The demons which haunt his universe are imperial elites, property markets (which he imagines as a causal agency, not an instrument) and racial ideologies. All of these factors, he believes, operate in a "top-down" and often co-ordinated way to advance the interests of the powerful and marginalise weaker groups. But not everything can be explained in those terms. For example, the violence which erupted on the streets of Northern Ireland in 1969, and entrenched segregation, may have had its roots in imperial policy, but it clearly had a local momentum of its own. It is nonsense to suggest, as he does, that the Protestant mobs that attacked Catholic areas in the early days of the troubles were "cheered on" by "right-wing British politicians" in London. Another gripe is that the book promises an account of "70 centuries of city-splitting" but fails to deliver on that, despite a perfunctory opening chapter which looks, among other things, at sacred space in prehistoric and pre-modern times. To state the obvious, Western imperialists were not the only dividers of cities. In traditional empires - Ottoman or tsarist, for example - cities were split because society itself was rigidly divided, although not always physically, into ethnically or religiously based communities where the individual's everyday life was controlled by the leader of his or her group, who in turn delivered the group's loyalty to the sultan or emperor. The elites of each group had a stake in enforcing separation. A comprehensive look at urban segregation would have teased out the difference between traditional and modern separation. Mr Nightingale's view of how power works makes his own task harder. He struggles to deal with the fact that the white elite in both Britain and South Africa were willing to make tactical concessions to non-whites when it suited them; the white workers who went on strike (under the slogan "Workers Unite for a White South Africa") to stop black workers being promoted in the mines in the early 1920s were brutally suppressed. In the present day, too, a "top-down" view of power has limits. Take Northern Ireland, where over 90% of a vast public housing stock is segregated by religion. Government officials in London and Belfast would love to change that, but it seems beyond their capacity to challenge the forces that keep most streets "pure." Urban division in this case is a measure of government weakness, not ruthless strength. Segregation is not always something imposed by those who hold political power over the weak and vulnerable.