'A Moment of War' is Laurie Lee's semi-autobiographical story about his involvement in what conflict?

'A Moment of War' (1991) by author Laurie Lee is the last book of his semi-autobiographical trilogy. It covers his time as a combatant in the Spanish Civil War from 1937–38. The preceding books of the trilogy are Cider With Rosie (1959) and As I Walked Out One Midsummer Morning (1969).

The book describes how, in December 1937, Lee set out for Spain to fight for the Republican cause. He could not persuade anyone to help him and so eventually crossed the Pyrenees alone in a snowstorm. After encountering Republican sympathisers, he was suspected of being a Nationalist spy and imprisoned. On the day scheduled for his execution, a fortunate encounter led to him being released and finally joining the International Brigade. The book then recounts Lee's experiences as a Republican soldier in Figueres, Valencia, Tarazona, Madrid, Teruel and Barcelona. He left Spain in February 1938.