Finsler geometry is a subject that concerns manifolds with Finsler metrics including Riemannian metrics. It has applications in many fields of natural sciences such as Biology, Econometrics, Physics etc. This invaluable book presents some advanced work done by the author in Finsler and Lagrange Geometry such as the theory of hyper surfaces with a beta change of Finsler metric, Cartan spaces with Generalized (?,?)-metric admitting h-metrical d-connection.In addition to above topics, four dimensional Finsler space with constant unified main scalars, conformal change of four dimensional Finsler space, a remarkable connection in a Finsler space with generalized (?,?)-metric, the existence of recurrent d-connections of the generalized Lagrange spaces and the L-duality between Finsler and Cartan spaces have been also discussed in detail. In particular the Finlerian hypersurfaces obtained by Matsumoto change of Finsler metric and the L-dual of Generalized Kropina metric have been discussed. This book will benefit the postgraduate students as well as researchers working in the field of Finsler, Lagrange Geometry and allied areas.