This paper explores the history of macroeconomics from Keynes to Lucas and beyond. It discusses different macroeconomic theories like Keynesianism, monetarism, new classical macroeconomics, real business cycle models, and new neoclassical synthesis models. The focus is on the differences between Keynesian and Lucasian macroeconomics. The paper also touches on how the current crisis is impacting the development of macroeconomic theory.