This course of lectures has been designed with a view to what is appropriate for students pursuing a research degree in applied economics. The topics covered range from the General Theory, through the challenge posed to it by the New Classical Macroeconomics, to the current status of the conventional wisdom on macroeconomic policy following the global financial crisis of the current decade. The emphasis will be on the theory, the concepts and their evolution. Some familiarity with the subject matter will be assumed.