This lecture proposes the term Big Translation History (BTH) to describe a translation history that can be analysed computationally and that I define as involving: (1) large-scale research (geographical and chronological); (2) massive data understood as big data, accompanied by little data, and drawing on a wide range of often heterogeneous and non-structured sources; and (3) the use of computational techniques as part of the research process, and for the production of knowledge, rather than helping only with visualisation of data. I advance the hypothesis that one of the main possibilities of BTH, as a conceptual framework and a methodology, is to help decentralize translation history and literary and cultural history, in a broad sense. The lecture goes on to present an analysis of the circulation of literary translations and the agents involved in the Spanish-speaking world between 1898 and 1945 as a case study in BTH, but it can be applied to other languages, periods, and geographical scales.