Isherwood’s memoir covering the period around his time in the gay scene of 1930s Berlin as the country was slowly overtaken by Nazis, ending in his leaving Germany and trying to get his boyfriend Heinz immigration to the UK to avoid him being conscripted by the Nazis. Part of it was fictionalised in his Berlin Novels (and adapted into the musical Cabaret).

It's this which really got me into the history of Weimar Berlin and the early gay rights movement there, but also writing that focuses on the calm day to day lives of unimportant but fascinating characters swept up in changes far above them.