I use the label ‘macrohistory’ for study of the past on very large scales. Macrohistory includes the scales of world history and historical sociology, as well as the even larger scales of ‘big history’, which embrace geological and even cosmological time. Macrohistory is interdisciplinary, because it crosses the boundaries between the humanities and the sciences. One of its main themes is what Jacques Revel has called ‘the play of scales’, the way in which our sense of significance, agency and causality can shift when we view the past on different scales and through different frames. This paper explores the current state of macrohistory and suggests how it may evolve as a teaching and research field. As a teaching field, macrohistory can enrich students' sense of their own identity and place in the larger scheme of things. As a research field, the methodology of macrohistory will be closer to that of historical sociology than to that of archival historical research. It will probably be dominated, at first, by scholarly raids into other disciplines that can help historians raise new questions and see old questions in new ways. The paper offers examples of macrohistorical research on different scales and includes a sample bibliography of macrohistorical scholarship.