A presentation of contemporary and critical assessments of Leon Trotsky, many of these writings have never previously been published in English, others have not reappeared since their first publication. Much of the material presented below – the articles by the German Communist Opposition, the open letter from the (at this juncture) dissident communist Boris Souvarine, the piece by the anarchist ‘Senex’ and the two retrospective articles by former POUM members – argues inter alia that Trotsky tended to view events rather too much through the prism of the experience of the October Revolution and the factional debates within the Soviet Communist Party, and that this seriously impaired his strategic and tactical acumen, especially in respect of the Spanish Civil War. Included are: Boris Souvarine’s lengthy letter to Trotsky; Articles on Trotsky from the German Communist Party (Opposition); Jay Lovestone on Trotsky and Soviet foreign policy; A Christian socialist critique of The Revolution Betrayed and defence of the Moscow Trials; An anarchist critique of Trotskyism and the Spanish Civil War, and; Assessments of Trotsky and the Spanish Civil War by two former POUM militants. In publishing the ‘other side’ of the arguments, this issue of Revolutionary History is continuing in its role of developing an understanding of key historical events and encouraging discussion of the past within today’s socialist movement.