Despite an extensive literature on homelessness there is surprisingly little work that investigates the roots of homelessness by tracking homeless people over time. In this fascinating and much-needed ethnographic study, Megan Ravenhill presents the results of ten years' research on the streets and in the hostels and day-centres of the UK, incorporating intensive interviews with 150 homeless and formerly homeless people as well as policy makers and professionals working with homeless people. Ravenhill discusses the biographical, structural and behavioural factors that lead to homelessness. Amongst the important and unique features of the study are: the use of life-route maps showing the circumstances and decisions that lead to homelessness, a systematic study of the timescales involved, and a survey of people's exit routes from homelessness. Ravenhill also identifies factors that predict those most vulnerable to homelessness and factors that prevent or considerably delay the onset of homelessness.