This book presents an upper level text on semilinear evolutionary partial differential equations aimed at the graduate and postgraduate level. Cazenave and Haraux present in a self-contained way, the typical basic properties of solutions to semi-linear evolutionary partial differential equations, with special emphasis on global properties. The main objective of this book is to provide a didactic approach to the subject , and the main readership will be graduate students in mathematical analysis, as well as professional applied mathematicians.