This concise self-contained book on life contingencies is written for students, teachers, researchers and life insurance practitioners. The stochastic model, introduced by Professor De Vylder more than twenty years ago and now widely adopted, is used throughout the monograph. Beyond the classical material of life insurance mathematics, the emphasis lies on variance evaluations of mathematical reserves, allowing the estimation of long term ruin probabilities in life insurance portfolios with varying volume. Other characteristics of the book are its great generality, the inclusion of an axiomatic theory of compound interests, the development of statistical methods for mortality and other estimations, and the introduction of graphs making a clear visualization of multiple decrement models possible. This approach makes the monograph incomparable to other books in the field.