 In 1977, his "Autobiografía de Federico Sánchez" ("Autobiography of Federico Sánchez") won the Premio Planeta, the most highly remunerated literary prize in Spain.In spite of the pseudonymous title, the work is Semprún's least fictionalized volume of autobiography, recounting his life as a member of the central committee of the Spanish Communist Party (PCE), and his undercover activities in Spain between 1953 and 1964.The book shows a stark view of Communist organizations during the Cold War, and presents a very critical portrait of leading figures of the PCE, including Santiago Carrillo and Dolores Ibárruri.