The tenth conference on The Mathematics of Finite Elements and Applications, MAFELAP 1999, was held at Brunel University during the period 22-25 June, 1999. This book seeks to highlight certain aspects of the state-of-the-art theory and applications of finite element methods of that time.This latest conference, in the MAFELAP series, followed the well established MAFELAP pattern of bringing together mathematicians, engineers and others interested in the field to discuss finite element techniques. In the MAFELAP context finite elements have always been interpreted in a broad and inclusive manner, including techniques such as finite difference, finite volume and boundary element methods as well as actual finite element methods. Twenty-six papers were carefully selected for this book out of the 180 presentations made at the conference, and all of these reflect this style and approach to finite elements. The increasing importance of modelling, in addition to numerical discretization, error estimation and adaptivity was also studied in MAFELAP 1999.