‘If I go to war, I go on condition I can have Giotto, the Basilica of Assisi book, Fra Angelico in one pocket, and Masaccio, Masolino and Giorgione in the other,’ Stanley Spencer wrote to the artist Henry Lamb in 1914. The sixpenny Gowans & Gray edition of the Masterpieces of Giotto now in a glass case in Somerset House’s exhibition Stanley Spencer: Heaven in a Hell of War is the one that travelled with him two years later to the Macedonian front, where its imagery fused with his memories of war.