At the Leicester urban history conference in 1966 there was very little discussion of the relationship between public policy and urban history. There were some points at which linkages were implied, but these arose merely incidentally. There was no attempt to adopt public policy as a general perspective on urban development. Reciprocally, the planners paid no attention to the historians: Jim Dyos remarked that the largest part of ‘research and policy making is taking place without reference to the historians’. The picture has not greatly changed over the past 14 years. There have indeed been studies in which policy, its formation and limitations, have been implicit, but few in which they have played a central part.

In the last ten years, a significant development in the study of urban history has allowed French historians to begin to consider some of the problems which have preoccupied their foreign colleagues, notably in Britain and the United States, for some time. The attraction of the town for the French historian is due, clearly enough, to two main factors. On the one hand, the town's growing dominance over the location of employment and population is bound to attract attention—in 1980 80 per cent of the population of France live in towns, exactly reversing the distribution of 200 years ago. On the other hand, this same distension of the town demands historical attention. It places the town at the centre of a very long-term development in which the urban criterion becomes increasingly dominant, defining a particularly appropriate field for the measurement of the linking mechanisms which regulate relationships between the different levels of social reality. Urbanity, in short, brings together the whole gamut of questions posed by the development of our system of civilization over the centuries. To reconstruct its history is to indulge in nostalgia for a past which appears all the richer in comparison with the drabness of our own day. It is also to dream of a city of the future, capable of reconciling community and social control, nature and culture. In France the history of towns is inseparable from a long process of examination which began with the humanist enthusiasm for the city, continued through the speculations of the Enlightenment and the tentative researches of nineteenth-century local anti-quarians, and has recently been supplemented by the more precise discoveries of the urban historian.

Measuring residential segregation is a challenging and crucial task. Many important questions in urban history can be understood fully only after correctly assessing the importance and significance of the clustering patterns of different groups of urbanites. However, the extent to which and the ways in which various social classes, races, and ethnic groups congregated in the expanding industrial metropolis of nineteenth-century America form the subject of heated debates among historians. With large black ghettos now existing in all major cities, experts and lay citizens alike agree that Americans live in a ‘separated society’. In the first half of the twentieth century, metropolitan areas took the form of ghettoized central cities with white suburbs. With the transfer of many urban functions to suburban units, and the shift of America from a nation of urbanites to a nation of suburbanites, a complex pattern of suburban segregation also developed. The universal concern about the magnitude of today's segregation makes the historical debate intriguing. Was it once different? Was there a time when cities were integrated? At some time in the past, many believe, American cities were better places in which to live—hence we should strive to recover our lost community.

The problem of social conflict is central to the historiography of nineteenth-century cities. Since Friedrich Engels wrote his powerful indictment of social relations in English industrial towns, urban historians have told and retold tales of dramatic struggles between workers and their middle-class employers. Whether seen from a Marxist or non-Marxist perspective, the standard books on social life in industrial towns abound with strikes, demonstrations, confrontations, and other more subtle signs of conflict. A. Temple Patterson and Malcolm Thomis depict the often tumultuous responses of Leicester and Nottingham framework knitters to their economic decline. Accounts of urban Chartism regularly link workers’ economic and social demands to strong middle-class disapproval and disavowal within a local context. Books on the 1830s and 1840s are particularly rich in incidents of confrontation, but the growing literature on the late nineteenth century also emphasizes this theme. Gareth Stedman Jones places middle-class misconceptions and fears at the centre of his analysis of casual labour in London, and Robert Grey's discussion of Edinburgh artisans assumes the reality of class conflict as a determinant of urban social relations. Nevertheless our understanding of divisions among urban social groups and of the relationships of one group to another remains primitive and unsatisfactory.

Now that the debate about the standard of living during the first half of the nineteenth century appears to have entered a relatively quiescent phase, historians have begun to turn their attention towards the more elusive concept of the quality of life. The incidence of fatal and non-fatal disease is clearly central to research of this type and so, too, is a delineation of the physical context in which infections have flourished and in which those who have been afflicted by them have lived. Although there has been a tendency to underestimate the ferocity of epidemics in rural areas in the period after about 1750, historians working on disease in the modern period are inevitably most usually concerned with processes which are specifically urban in character. And urban historians, especially those interested in such topics as the development of utilities, the growth of administrative bureau-cracies or the spatial segregation and different life experiences of the classes, can undoubtedly benefit from a knowledge of patterns of infection in the past.

The planning system which dominates most of the comtemporary world is of European and American origin. It has come out of the particular socio-historical background of these Western countries and has naturally had some implicit assumptions regarding the concepts, purposes and ideology of planning. This system has been exported to, and often imposed upon, countries with different social conditions where those assumptions are not necessarily valid. As a result, in many developing countries, planning is considered ineffective, and planners become frustrated.

The fortunes of late medieval towns seem to have become rather a contentious topic. That is probably a good thing. It is a poor historical proposition that cannot be illustrated by some evidence, but proof of an historical phenomenon like general decline or decay requires something more than illustration and something that argument may help to secure. So far, however, as S. H. Rigby points out, the debate has suffered from an uncertainty over terms that may frustrate the advance of knowledge and understanding. Two words which he did not mention but which seem to me particularly unclear are ‘decline’ and ‘decay’ themselves. Until they are examined more closely we may not be sure enough of what anyone is trying to prove to know whether he has succeeded or not.

Since the mid-sixteenth century London has received attention from many map-makers and publishers. Before the arrival of the Ordnance Survey, however, only a handful of London maps are both topographically reliable (in terms of contemporary technical ability) and based on original surveys. These are: the lost mid-Tudor copper-engraved map, original of the so-called ‘Agas’ woodcut map, Hollar's uncompleted map of 1661–6, Rocque's maps of London and its environs of the 1740s, and the two post-Fire maps considered here. Of this group only ‘Agas’ and Rocque's maps are familiar and fairly widely used by historians, although, one has to say, more often as book-illustrations for their ornamental and quaint character than for the information they give.

Title deeds are an invaluable source of information on the evolution of local housing markets. They are also a key to three other data sources. First, they complement plans registered with a local authority before a house was built. Second, by recording the deaths of most rentier landlords they give an entry point into the Probate Registry. Third, they check property ownership as listed in rate books. Finally, they are complementary in a more general sense. They are reliable (because solicitors take special care to see that the facts are correct) and each event in the history of a house is made intelligible by being recorded as part of a time sequence. But information is limited to one house or at most a block. Only by painstaking accumulation of a large number of deeds is it possible to discern economic patterns. Even then a sample of deeds drawn from a whole city might be insensitive to the finely balanced economic equations of, for example, landlords' rental income and their offsetting payments to mortgagees, agents, and ground landlords. Confined to a more manageable suburb, a sample of deeds may be atypical of the city. On the other hand, complementary data from the other registers is comprehensive, covering big geographic areas and large numbers of houses or people. But it comes as snapshots, aggregated appearances which are difficult to make socially or economically intelligible: the atomised names of otherwise anonymous builders on a building plan, landlords in a rate book, and property owners in the Probate Registry.