Hitler's accession to power brutally sealed the fate of the German Communist Party (KPD). With 360,000 members, the strongest affiliate of the Communist International (Comintern) was dissolved in March 1933, its militants interned or executed. 1 Its liquidation was the most tragic West European consequence of the disastrous, ultra-left policy of the Third Period, determined by the Comintern, rooted in Russian considerations and accepted, sometimes with reluctance, by national communist parties. Such has been the verdict of a wide range of historians. It is a conclusion which has recently come under attack from academics anxious to revise our understanding of these turbulent years. 2 This article engages with this new revisionism. We sketch the anatomy of the Third Period and its consequences for European communist parties. Next, we outline the arguments of recent historians who, contrary to traditional judgements of the impact of the Comintern's 'new line' upon the Communist Party of Great Britain (CPGB), suggest both that there were strong indigenous pressures inevitably leading to its adoption and that its consequences were more positive than previously assumed. We go on to subject these arguments to critical scrutiny in the light of evidence from the recently accessible Comintern archives. Our survey reaffirms the validity of previous evaluations of the Third Period.