The article introduces Keynesian Economics, a theory developed by economist John Maynard Keynes in the 1930s during the Great Depression. Keynes proposed that a healthy economy and full employment depend on total spending by consumers, businesses, and governments. This approach was widely adopted by governments until the late 1970s when Monetarism became popular but was not as successful. Keynesian Economics made a comeback due to its effectiveness. Keynes was a brilliant economist and a colorful figure in history. The book "Introducing Keynesian Economics" provides a clear explanation of Keynesian principles and his life, making it a great introduction for students and general readers.