"Buddenbrooks: The Decline of a Family" (1901) laid the foundation for Thomas Mann's extraordinary career as a writer and representative of German literature and culture worldwide. The novel is not only among the Nobel Prize-winning and most-read works but also one of the most interpreted texts in German literature. This handbook consolidates extensive research on the novel and presents, alongside its history of creation and reception, the central themes and structures. It addresses not only family, economy, and religion but also seemingly marginal topics such as food and drink or elements of the fantastic. Additionally, the handbook opens interpretative and literary theoretical approaches to the text, ranging from social history to theories of memory and recollection, as well as constructions of femininity and masculinity, to knowledge.