This book deals with the classical plate theory most commonly used for the analysis of thin metallic plate structures. The basic assumptions of the plate theory are not straightaway taken for granted, but are deduced as logical inferences from a three-dimensional elasticity solution for a thin rectangular slab. In addition, the elasticity results are used to verify the accuracy of the plate theory. Statics, dynamics as well as stability of plates are dealt with. Besides a lucid explanation of the theory, exact and approximate solution methodologies are discussed. The approach adopted throughout - with emphasis on close correspondence with the three-dimensional theory of elasticity, and on the implications of each assumption of the plate theory - enables the reader to easily progress on to the study of state-of-the-art topics such as geometric and material nonlinearities, refined plate theories accounting for warping and stretching of the normal and laminated construction and material orthotropy typical of fibre-reinforced composites.