Leopold von Ranke (Prussian, 1795-1886). Ranke, the father of objective historical inquiry, wrote sixty works in all, including the multi-volume studies History of the Popes, History of England, History of the Latin and Teutonic Nations, and History of Servia and the Servian Revolution. Relying almost exclusively on archival sources, he took a "just the facts" approach: "You have reckoned that history ought to judge the past and to instruct the contemporary world as to the future. The present attempt does not yield to that high office. It will merely tell how it really was."
Joseph Needham (British, 1900-1995). Needham began his colossal study Science and Civilisation in China after returning from work in China for the Foreign Office during the Second World War. Each of the seven wrist-breaking volumes comprises multiple subvolumes, so the entire seventeen-book set occupies a fair-sized bookcase. Civil Engineering and Nautics (Vol. 4, Part III) still offers the best explanation of why China led the world in oceanic exploration in the fourteenth century.
Nikolaus Pevsner (German émigré to London, 1902-1983). Already an astonishingly wide-ranging author of architectural history when he left Germany, Pevsner was appalled that there was no authoritative guide to the churches, country houses, and other architectural treasures of England. With his wife, and eventually with research assistants as well, he made up for that deficit, visiting each notable (and not-so-notable) building, county by county, over the course of forty years. The result is the forty-six-volume The Buildings of England, which mixes technical commentary with lyrical and sometimes sardonic language. (Holy Trinity Church, in Oare, "may well be considered the ugliest church in Wiltshire.") A staggering achievement.
Arnold Toynbee (British, 1889—1975). Toynbee's twelve-volume work on the rise and fall of civilizations, A Study of History (various abridged versions exist for the weak-hearted), was once regarded as immensely important and prophetic, especially by many American readers during the early Cold War. It then suffered the powerful critiques of the great Dutch historian Pieter Geyl, and fell out of fashion. It remains, however, a work of remarkable erudition. All the more impressive is that Toynbee wrote it while he was serving as director of studies at the Royal Institute of International Affairs and writing the institute's annual "Survey of International Affairs." He would spend half a year composing, say, a volume on ancient Persian and Sumerian civilizations, and the other half describing the current Ethiopian crisis. Did folks like him sleep?
Fernand Braudel (French, 1902—1985). Braudel's largest work was the formidable (and beautifully illustrated) three-volume world history Civilization and Capitalism, in which he revealed a Toynbee-like capacity to discuss the port cities of Hamburg and Goa in the same sentence. But his greatest volumes are the two that make up The Mediterranean and the Mediterranean World in the Age of Phillip II, which not only looked at that richly varied region in a synoptic, comparative way but also taught us to think about different levels of history, with the seasons and the weather, relative constants, at the base level; technology and commerce, ever evolving, at the intermediate level; and high politics—reflected, say, in the Battle of Lepanto and the Spanish Armada—at the upper (though in his view somewhat superficial) level.