The theory of relativity has revolutionized the whole gamut of Physics namely, mechanics, electromagnetism, astronomy, astrophysics cosmology and even quantum mechanics. This book comprehensively explains the evolution of the theory of General relativity from Special relativity, as was given by Einstein. Beginning with an introduction of elementary concepts of special and general relativity the book goes on explaining the advanced topics, giving a stepwise derivation of all the equations. The review questions section is designed to help the students grasp the knowledge on advanced theories of relativity. This book is intended for the undergraduate and postgraduate students of Physics and Mathematics.