In the sub-field of world history, there has been a surprising paucity of thinking and writing about how to approach and conceptualize the long twentieth century from the 1870s through the early 2000s. The historiographic essays collected in Essays on Twentieth Century History will go a long way to filling that lacuna. Each contribution covers a key theme and one or more critical sub-fields in twentieth century global history. Chapters address migration patterns, the impact of world wars, transformations in gender and urbanization, as well as environmental transiti