The Great Transition: Climate, Disease and Society in the Late-Medieval World by Bruce M. S. Campbell (review)

Bruce Campbell is an emeritus professor of British medieval economic history at Queens University, Belfast, known for detailed inquiries into manorial records. In addition to studies of yields, prices, and other standard fare of agrarian economic history, he has for some time now taken into account English medieval climate and epidemics. In this book, he expands his horizons dramatically, focusing directly on climate changes and bubonic plague as they interacted across the length and breadth of Eurasia. In venturing far beyond his familiar turf into large-scale climate history, Campbell resembles Geoffrey Parker and John Brooke who have recently published sprawling syntheses of global history, for the seventeenth century and for all of human history respectively, and put climate at the center of their stories.¹ Now medievalist Campbell enters the lists, with another hefty and demanding tome.

It is demanding because it integrates data and perspectives from paleoclimatology, microbiology, plague ecology, and a few other fields, most of which will be unfamiliar to most historians. He reviews rates of varve deposition on the coasts of Pakistan and speleothem chemistry in Wanxiang Cave. He burrows deeply into plague DNA studies and the habits of relevant rodents, fleas, and bacilli—including recent genomic studies of plague that seem to resolve the longstanding question of the origin of the Black Death (eastern Tibetan/Qinghai plateau). He also presumes a formidable knowledge of place-name geography of Eurasia. You're on your own if you don't know that Sarai Batu was on the lower Volga.

A venerable macro-historical question animates Campbell's work: Why Europe? He provides an extremely detailed answer that boils down to the notion that the plague and adverse climate in the fourteenth and early fifteenth centuries hammered every part of Eurasia, forcing a realignment—the Great Transition—of what he calls the socio-ecological regime. In that realignment, Brabant, Holland, and England emerged as the fastest-growing and soon richest parts of Europe, eclipsing northern Italy, and the most dynamic places in the world economy, more so than anywhere in Asia. Thus the Great Transition led to the Great Divergence, which for Campbell came centuries earlier than it did for Pomeranz.

The argument is best understood by following Campbell's chapter structure. He devotes more than 100 pages (chapter 2) to the efflorescence of Latin Christendom. Thanks in large part to favorable climate and improving, or at least fairly reliable yields (the yield data come mainly from England), population and urbanization grew in most of Europe from 950. Times were best from about 1100 to 1250. This chapter includes a bumper crop of graphs and tables, as one expects from an economic historian.

The good times stopped rolling after 1250. The Great Transition begins in chapter 3, which runs to more than 130 pages. Climate is the chief culprit, beginning with the fallout from an Indonesian volcanic eruption in 1257, followed by more systemic changes from 1270 or so. Less stable climate undermined agricultural prosperity through repeated harvest shortfalls and at the same time created conditions more propitious to the spread of epidemics and epizootics, notably the great cattle plague of the early fourteenth century that wiped out the majority of European livestock. These were hard times for ordinary people.

Then in the 1340s, bad times got worse. War, more adverse climate, and plague combined in what Campbell calls "a perfect storm." That occupies chapter 4, a mere 65 pages in length. Campbell makes a strong case, following the geneticists, that the irruption of plague began on the flanks of the Tibet/Qinghai plateau when drought killed wild rodents and drove their (plague-carrying) fleas to seek new hosts. Plague kept coming back, so that by the 1380s, Europe's population stood at only half its 1345 level. This chapter serves nicely as a summary of the recent literature on the...