“Rereading the General Theory”, wrote Milton Friedman (1997, p. 5), “has reminded me what a great economist Keynes was.” His Chicago colleague, Judge Richard Posner (“How I became a Keynesian” 2009), when driven by the Global Financial Crisis to actually read Keynes’s The General Theory of Employment, Interest and Money, was shocked to discover that he found the book admirable, readable and helpful in understanding the world, and even was converted to Keynesianism (not at all an effect that rereading the book had on Friedman). That Keynes was an economist of sufficient historical influence, both of attraction and repulsion, to warrant inclusion with David Ricardo or Alfred Marshall in The Elgar Companion series hardly seems debatable. We cannot imagine a three-volume biography of any other economist, however well written, being published, let alone being a best seller (Skidelsky 1983–2000, 2003). The evolution of modern macroeconomics cannot be understood without reference to Keynes’s influence – and in the case of monetarism and New Classical economics, to reactions against his influence (see Skousen, Dissent on Keynes, 1992). The Global Financial Crisis has provoked an outpouring of books with titles such as Keynes: The Return of the Master (Skidelsky 2009), Keynes: The Rise, Fall and Return of the 20th Century’s Most Influential Economist (Clarke 2009), Maynard’s Revenge. The Collapse of Free Market Macroeconomics (Taylor 2010), The Return to Keynes (Bateman et al. 2010), The Fall and Rise of Keynesian Economics (Eatwell and Milgate 2011) and Keynes Hayek: The Clash that Defined Modern Economics (Wapshott 2011). Yet even if Keynes had never written General Theory, he would have been historically important as the critic of the Versailles Peace Treaty and author of the Economic Consequences of the Peace, and as a leading Treasury advisor and international negotiator during and after two world wars. His interests and activities, notably as a philosopher and as a cultural entrepreneur, ranged far beyond economics. The Elgar Companion to John Maynard Keynes surveys and samples the scholarship on his life and legacy, the influences on his intellectual development, and the nature and context of his contributions. This body of scholarship, anchored by the great biographies of Keynes by Donald Moggridge (1992) and Robert Skidelsky (1983–2000), has benefitted from the 30 volumes of The Collected Writings of John Maynard Keynes (1971–89, general editors Donald Moggridge and Austin Robinson, volume editors Donald Moggridge and, for four volumes, Elizabeth Johnson), supplemented by T.K. Rymes’s reconstruction of Keynes’s lectures in the early 1930s (Rymes 1989), and by much now-available unpublished material such as declassified Treasury files (see Lekachman 1964, for an overview of earlier studies of Keynes as an economist). It has also benefitted from a changed, and deepened, understanding of Keynes as an economist, notably by Axel Leijonhufvud’s distinction between Keynesian economics (the economics of the mainstream of those who considered themselves Keynes’s followers) and the economics of Keynes himself (Leijonhufvud 1968; see also Minsky 1975, Friedman 1997 and Harcourt and Riach 1997 for other perspectives on the economics of Keynes). Views of Keynes the man also evolved: contrast Jeff Escoffier (1995) on Keynes as a gay man with the reticence of Harrod (1951). Too much can, and all too often has, been made of this: Keynes’s pre- Lydia homosexuality can explain his break from the economic orthodoxy of Pigou and Robertson only if a similarity can explain a difference. The Bloomsbury group, a crucial context for Keynes, is now much better known and understood than it was.