This research project will examine the history of dense wood-built housing in twentieth-century Tokyo to see what lessons can be drawn for contemporary and future cities. Tokyo was one of the first "megacities," with a population over ten million, and it remains one of the largest cities in the world today. The city lacks a clear overall street plan. Many residential neighborhoods were built by local builders in the first half of the twentieth century with limited or no municipal infrastructure or planning controls. The city's Social Bureau classified roughly two hundred blocks in these neighborhoods as slums in the 1930s. A few were rebuilt with public housing, but in most, infrastructure was introduced without replanning of the street network and housing and social conditions gradually improved. Few would be considered slums by world standards today. This project therefore asks, first, how did these neighborhoods come to be built and how were they incorporated into the municipal infrastructure; then, how did they disappear into the fabric of the city, ceasing to be identifiable slums? Close study of these historical processes at the local level together with a review of the history of planning, property law, and urban social policy as they affected these places will offer material for defining a ''Tokyo model" of modem urban development without slum clearance. I contend that this will have greater relevance to efforts to study and ameliorate the conditions in the slums of contemporary megacities elsewhere in Asia than conventional planning models adopted from the West. Based on the Social Bureau surveys, I plan to identify a group of between four and eight districts for microhistorical studies, tracing the development of each from the time the first houses were built until the late twentieth century. After background research in local archives, I will lead a group of Japanese graduate students in intensive fieldwork in these districts, studying the street layout, lot divisions and architecture for traces of the original development and interviewing residents about changes since World War II. I will combine the results of these microhistories with studies of urban policy and the reconstruction plans that followed the earthquake of 1923 and the war to develop a broad picture of the continuities and discontinuities in dense wood-built neighborhoods over the century. Determining the historical origins of common patterns in Tokyo's development will then enable me to consider Tokyo's case in comparative perspective. After I have completed the foundations of the study in Tokyo, I plan to visit other Asian cities with histories of dense wood-built unplanned districts to learn from local planners and study the contents of municipal archives in those cities. In addition to providing material for comparisons in my own monograph on Tokyo and for future articles, I hope that these visits will also initiate a useful dialogue about strategies for incorporating densely built unplanned districts into the city without evictions or wholesale demolition.