Rosa Luxemburg as well as Lenin developed from the Social Democracy, in which both played important roles. Their work influenced not only the Russian, Polish and German labour movement, but was of worldwide significance. Both symbolised the movement opposed to the revisionism and reformism of the Second International. Their names are inseparably entwined with the re-organisation of the labour movement during and after the World War, and both were Marxists to whom theory was at the same time actual practice. Energetic human beings, they were — to use a favourite expression of Rosa Luxemburg's — 'candles that burned at both ends'.