terms throughout their lives and were still married when Mann died in 1969. She left him a small bequest in her will. In 1936, Auden introduced actress Therese Giehse, Mann's lover, to the writer John Hampson and they too married so that Giehse could leave Germany. From 1935 until he left Britain early in 1939, Auden worked as freelance reviewer, essayist, and lecturer, first with the GPO Film Unit, a documentary film-making branch of the post office, headed by John Grierson. Through his work for the Film Unit in 1935 he met and collaborated with Benjamin Britten, with whom he also worked on plays, song cycles, and a libretto. Auden's plays in the 1930s were performed by the Group Theatre, in productions that he supervised to varying degrees. His work now reflected his belief that any good artist must be "more than a bit of a reporting journalist". In 1936, Auden spent three months in Iceland where he gathered material for a travel book Letters from Iceland (1937), written in collaboration with Louis MacNeice. In 1937, he went to Spain intending to drive an ambulance for the Republic in the Spanish Civil War, but was put to work writing propaganda at the Republican press and propaganda office, where he felt useless and left after a week. He returned to England after a brief visit to the front at Sarineña. His seven-week visit to Spain affected him deeply, and his social views grew more complex as he found political realities to be more ambiguous and troubling than he had imagined. Again attempting to combine reportage and art, he and Isherwood spent six months in 1938 visiting China amid the Sino-Japanese War, working on their book Journey to a War (1939). On their way back to England they stayed briefly in New York and decided to move to the United States. Auden spent late 1938 partly in England, partly in Brussels. Many of Auden's poems during the 1930s and after were inspired by unconsummated love, and in the 1950s he summarised his emotional life in a famous couplet: "If equal affection cannot be / Let the more loving one be me" ("The More Loving One"). He had a gift for friendship and, starting in the late 1930s, a strong wish for the stability of marriage; in a letter to his friend James Stern he called marriage "the only subject." Throughout his life,