The history of Karl Marx's great work Capital was for Engels a living reality that was being created before his very eyes. But Engels was by no means an outside observer of it, but took a very direct and active part in it, fully created it together with Marx, and as a result made an independent contribution to the development of Marxist theory and the method of economic research, and hence to the history of Capital. At the same time, Engels became the founder of the scientific study of Marx's economic legacy (its content and history of its creation), and also developed the basic principles of its scientific publication and creative application to the analysis of modern processes. It is these questions related to the history of "Capital" that are addressed in this article. The topic "Engels and Capital" has been extensively studied in our literature .1 Nevertheless, Engels ' development of the history of the creation of "Capital" and the course and methodology of Marx's work need further study. "The full coverage of Engels' role as a historian is also important and relevant because this role is still either hushed up or extremely belittled by representatives of bourgeois as well as reformist historiography."2 An important task of Marxist social science remains to elucidate Engels ' fundamental contribution to the history of Marxism, including the history of Marx's economic teaching. This is also due to the fact that Engels ' views on the history of Capital are an adequate reflection of this history itself. According to Engels, Marx's systematic study of political economy began in 1843.3 . A year earlier, Marx had set himself the task of"theoretically substantiating communist ideas," 4 in other words, creating a theory of scientific communism. The first step in the solution of this grandiose task, which required Marx to complete his entire life, was the study of- 1 Kazmina I. G. Engels ' work on preparing for the publication of the third volume of Marx's Das Kapital. ... Read more