"General Relativity" is a complete revision and extension of Straumann's well-known classic textbook "General Relativity and Relativistic Astrophysics." It is intended for physics and mathematics students eager to become acquainted with the foundations of general relativity and its major applications in astrophysics and cosmology. The foundations are thoroughly developed together with the required mathematical background from differential geometry developed in Part III. The author also discusses the tests of general relativity in detail, plus he includes the latest findings on supermassive black holes and the first double-pulsar system. Much space is devoted to the study of compact objects, especially to neutron stars and to the basic laws of black-hole physics. This well-structured text and reference enables readers to easily navigate through the various sections as best matches their backgrounds and perspectives, whether mathematical, physical or astronomical.