This essay focuses on the formation of the Historians' Group's proposition of 'battle of ideas' in the period 1946-1958. The central theme examines, in order to fight their battle of ideas, how the Communist historians' studies of Seventeenth-Century English Civil War and interpretations of Antonio Gramsci's ideas were elaborated in response to the shifting social and political contexts of the time. This essay thus explores the contexts in which the English Civil War and Gramsci's ideas were read, and will seek to demonstrate why the English Civil War and Gramsci's ideas were interpreted in a particular way. In conclusion, it is argued that, for the Communist historians, it was the contemporary political relevance of history and ideas that was most influential. The Communist historians' studies of the English Civil War and use of Gramsci's ideas both reflected their proposition of 'battle of ideas' and need for legitimatisation.