From the October Revolution to the Second World War
The first key point in the history of the parties and movements following Marx took place in 1917 with the October Revolution; it was followed, in 1919, by the founding of the Third (explicitly Communist) International in Moscow. These two events manifested the split between left-wing forces at the international level and resulted in the development of two main competing currents.
Numerous other theoretical approaches and attempts at political organisation have been conducted and they should neither be overlooked nor side-lined. In fact, during the 1920s and 1930s, “Marxism” continued to diversify in both theoretical and political terms. Moreover, Marxist thought became anchored more than ever before in institutions undertaking research and education.
Above all, however, this period is characterised by failed revolutions and revolts, such as those that took place in Germany, Hungary and Finland, later in Italy, in China during the 1920s and, latterly, in Spain. Moreover, a fatal development occurred during this time: the interwar period was the first in which the theory of emancipatory social progress (which was already partially dogmatic) developed into a legitimising ideology for an oppressive, dominant regime.