This is an interesting and original book authored by two political scientists. Its terminology and modes of argumentation are not those familiar to historians but the work's basic thesis is at least plausible and perhaps even persuasive. For me, it was challenging to contend with ‘difference-in-difference design’, ‘linear probability models’, ‘indicator variable analysis’ and ‘exclusion restrictions’, to mention just a few unfamiliar terms. Nevertheless, to come straight to the surprising point, here is the basic argument: ‘without the Catholic Church, modern representative government and the modern multistate system in which it occurs is well-nigh inconceivable’ (p. 179).

Only sixteen towns had autonomous councils in 1100 but 136 had them in 1200. The failure of state authority in the post-Carolingian world cannot alone explain this fact. The Catholic Church played a decisive, if sometimes unanticipated, role in effecting the widespread change to practices of self-government, representation and consent. The authors offer a summary of the rise and spread of church reform beginning with Cluny and going right through the Gregorian reform and the Investiture Controversy. The authors have constructed a data set of 680 European towns from roughly 1000 to 1800. They present their data in charts, tables and maps. The sample includes 199 episcopal towns and 481 non-episcopal towns. Of the towns 186 had gained self-governance between 1100 and 1300. Of sixty-two transitions that took place to 1150, fifty occurred in episcopal towns with sixty-eight of ninety-three by 1200. An interesting set of data shows that towns within 100km of one of the 270 Cluniac houses were most likely to transition. Cluny, of course, stood for freedom from lay control. That was also one of the key dimensions of the Church-State struggle of the high Middle Ages. Reform popes encouraged townsfolk to reject non-reformed clergy, which was a significant impulse to urban transition. The torrent of litigation unleashed by the Investiture Controversy brought Roman law to the surface in unprecedented ways. From Roman private law ideas of representation and consent spread widely. The Church also modelled representation and consent in its councils, chapter meetings and in the organisation of the Dominican order. Clerical and lay elites came from many of the same families and shared values and outlooks.

The Investiture Controversy seriously weakened the idea of empire with its hegemonic implications in much of Europe. In the tenth century Germany was Europe's most powerful state whereas by 1300 it was weak and divided. Indeed, between 1220 and 1302 no emperor was crowned. Individual realms gained practical and theoretical autonomy in the twelfth and thirteenth centuries. Even Pope Innocent iii accepted the idea that ‘the king is emperor in his own realm’. So, just as church reform of one kind contributed to urban autonomy, so reform of another kind resulted in the multistate system. While the papacy did weaken the empire it did not itself wind up as a sole effective ruler. The Great Schism and the Conciliar movement plus the writings of men such as John of Paris, Marsilius of Padua and William of Ockham challenged papal monism and delegitimised papal temporal rule.

The authors cite a good deal of international relations literature to show that, typically, bellicist or endowment theories are adduced to explain European state formation. The former maintain that war and its associated phenomena generate states whereas the latter point to geography and economic resources. This book tries to show that religion, specifically threads of religious reform, were actually decisive in medieval Europe. For the pre-Gregorian era of reform the authors draw on the work of John Howe and Robert Bartlett. For the book's later material they hew closely to the work of Francis Oakley and Brian Tierney. They have read very widely and medieval historians will find aspects of their arguments quite familiar. What will be new is the whole package, so to speak, and the emphasis on religious rather than secular issues. I kept thinking how very different this book's arguments are from those of Joseph Strayer's On the medieval origins of the modern state (1971). The authors use the word ‘unanticipated’ several times. I applaud their candour. But I do wonder about intentionality. Have Møller and Doucette heaped up a very tall pile of coincidences? I cannot think of a single source that promotes or even observes the thesis articulated in this book. In fairness, the authors’ research is not based on primary sources. They synthesise a large literature. Still, circumstantial evidence is admissible in court and the authors have a huge amount of it.