This is a dataset comprising linked event records for 1% of the population of England and Wales (about 500,000 people at any one census). It was set up in 1974 to address problems with the adequacy of occupational mortality data, and the lack of longitudinal fertility data, but since then it has been used to address a wide range of other research questions. Topics cover: all information from census returns since 1971, including data on occupation, economic activity, housing, ethnicity, age, sex, marital status and educationevent data on births and deaths, fertility, mortality, morbidity, migration and cancer registrationsecological data: population density, urban/rural indicator and deprivation indicator