In 1921 Riazanov established the Marx-Engels Institute, which became one of the main institutions of Soviet philosophy and history. Riazanov dedicated himself especially to the compilation and publication of the collected writings of Karl Marx and Friedrich Engels. In this context, as early as 1926, the publication of a multi-volume series called the "Marx-Engels Archive", collecting scholarship on the biography and writings of the founders of Marxism, began under Riazanov's supervision. In 1927 the first volume of the "Marx-Engels-Gesamtausgabe" ("MEGA1") was published by the Marx-Engels Institute, a complete edition of the works of Marx and Engels in their original languages, which was to comprise 42 volumes. Under Riazanov's editorship, five volumes of this edition were issued until 1931 (later seven more were published until the project was abandoned in the mid 1930s). Moreover, starting in 1928, a first Russian edition of the collected works of Marx and Engels in 28 volumes ("Sochineniya1") began being published, of which ten volumes were issued under Riazanov's direction until 1931 (vol. I–III, V–VIII, XXI–XXIII ; the edition was largely completed in 1947).