There is little not to like about Darius Baronas and S. C. Rowell's impressive new study of the conversion of Lithuania in the 1380s, famously Europe's last pagan state and at that date also its largest. Despite assaults by the Teutonic Knights, Tartars and Polish kings, in the fourteenth century the Lithuanians forged a political hegemony over Orthodox cities and princedoms in present-day Ukraine, Belarus and western Russia. They created a polity covering areas so vast, and geographies so diverse, that it can be hard for historians of western Europe to take them in. In 1386 Grand Duke Jogaila of Lithuania married Poland's Queen Hedwig of Anjou, was baptised into the Latin rite and crowned king of Poland. From 1387 he set about establishing the Latin Church in his Lithuanian domains. The conversion of Lithuania was extolled by Polish chroniclers, invoked in later royal panegyrics, and heavily romanticised in the nineteenth century. Baronas and Rowell set out to deepen, update and significantly complicate our sense of this famous story of the end of paganism in Europe.

In terms of academic genre, this book is hard to classify, and maybe therein lies some of its intellectual liveliness. It is a grand-scale survey of medieval Lithuania in its wider Eurasian context, but also a close critique of the conversion's historiography and sources, an essay on the nature of late medieval religions, and a major piece of new research on pre-Reformation Lithuanian Christianity, based on previously unexploited Vatican and Polish sources. The first eight chapters are written by Darius Baronas and span from the earliest origins of the Baltic tribes to the 1410s. Baronas explores the rise of Lithuania (asking what kind of state or ‘thing’ it was), and its relations with the Latin and Orthodox worlds over centuries of contact prior to the 1380s: telling a story not just of grand dukes and popes, but also of missionaries, martyrs and travellers. S. C. Rowell contributes the book's introduction and chapters ix to xii, which use an imaginative range of sources to investigate what kind of Catholicism existed on the ground in Lithuania in the relatively short window (130 years) between conversion from paganism and the Reformation. He seeks ‘to peek, however darkly, into the minds of ordinary Christians’, looking at petitions to Rome, fraternities, alms houses, clergy and parish life. We have here, then, a long history of the conversion of Lithuania.

This is one of a recent harvest of books published in English which set out for international audiences the latest research on the medieval and early modern history of what is often called Central Europe. The conversion of Lithuania stands out among them for a number of reasons. It is not always true that academic books over five hundred pages long are a riveting read throughout, but here the material is handled with real deftness, insight and wit. Places and events which will likely be unfamiliar to most English-language readers are here rendered not only comprehensible but also compelling: the steppe and forest brought to life. The book is clearly structured, and Baronas in particular keeps his (potentially crushingly big) narrative under tight control: zooming in and zooming out with enviable skill. The footnotes reveal, however, how enormous a labour this book is, and what level of scholarly expertise it has required – a knowledge not only of the latest archaeological, ethnographic and historical research disseminated in Lithuanian, but also of Polish, German and English scholarship, among others. The text, furthermore, draws on Latin, Byzantine and East Slav medieval sources alike. The reader is guided delicately through the key, often highly politicised historiographical debates. Particularly stimulating is Baronas's willingness to question the most basic aspects of the conversion story. By taking apart the influential account in Jan Długosz's Annales Regni Poloniae (a chronicle which could do with still more deconstruction by medievalists), he concludes that Lithuanians likely did not have pagan temples or clergy, and starts to ask in what sense (or in whose definition) tribal practices constituted an organised religion. This book is keenly alert to literary topoi on pagans and conversions in Latin and Greek sources alike, spotting them where many before have failed to do so. Rowell, meanwhile, offers a fine-grained account of religious life in this part of Christendom, exploring its syncretic aspects, finding Lithuanians to be highly engaged late medieval Catholics – even if Reformation sources would later claim otherwise.

Late medieval Lithuania sits at the rather daunting intersection of Orthodox, Latin, pagan and Mongol culture, and so to highlight areas where one might have wanted a little more coverage, in what is already a volume spanning such a large space and time, seems churlish. This reader would have found useful, in the introduction, a full state-of-the-art discussion of medieval conversion studies, locating Lithuania explicitly within them. Some consideration, in passing, of how Lithuania might compare with near-contemporary conversions of ‘pagans’ in the Canary Islands, or just a few decades later in the Caribbean and Americas, might have been fruitful, for those fields are richly and subtly researched. The Mongol heritage of the grand duchy of Lithuania might also leave some readers wanting to learn more: the points made in passing on this score were suggestive and intriguing. The work of Marie Favereau has more to say on this issue.

As a big, synthetic-interpretative study, The conversion of Lithuania seeks to make late medieval Lithuania and its religions more visible in international scholarship on the Middle Ages, and to demonstrate their innate interest and importance. It does this by locating Lithuania, and its diverse peoples, within wider questions about pre-modern religion, medieval sources and the pre-modern state. More tacitly, it also poses a question about what we understand by Europe, and where we locate its boundaries. With its engaging style, forensic source critique, new sources, new interpretations and fine maps, this book surely deserves to become a landmark text on this topic. This co-written project was supported by the EU's European Social Fund and published by the Institute of Lithuanian Literature and Folklore, and it is a book of which both funder and publisher should be very proud.