Lenin stated that the October Revolution of 1917 could never have taken place without the previous experience of the Revolution of 1905. A study of this remarkable event is therefore of great importance for anyone who wishes to understand the dynamics of revolution in general, and not just in a particular case. In the struggle for revolutionary ideology, a place of honour is occupied by the marvellous writings of Leon Trotsky. And among these, one of the most important is 1905, which we publish here.