What do we know about human longevity? The scientific community regularly meets to examine and re-examine this question, which persists in intriguing us.

Thus in October 1977, the Council of the International Union for the Scientific Study of Population (IUSSP) created a scientific committee on factors affecting mortality and the length of life to allow demographers and actuaries to develop closer links with social and biomedical disciplines. The resulting book, Biological and social aspects of mortality and the length of life, became a reference work for many years.

Twenty years later, in 1999, the IUSSP convened a new scientific committee on longevity and health, with the scientific objectives of studying human longevity, the dynamics of health transitions, the emergence and proliferation of centenarians, and demo-epidemiological projections, with the forecast of future health status.This book has resulted from the work of the committee focusing on longevity.

Such a book gathering the current knowledge from several perspectives - biology, demography, medicine, sociology - form a crossroads for the diffusion of new ideas and hypotheses.