Writing a monograph is a tough challenge, but squeezing an entire scholarly field in less than one hundred pages is a daunting one, which only a few historians would accept. The task becomes a quixotic enterprise, when one aims not only to summarize the state of art in such a short volume, but also to challenge the current assumptions. Christian Raffensperger took on such a scholarly bravery and, to his praise, managed to write an easy to read and highly stimulating short book.
The main contention of The Kingdom of Rus'is a polemic one: the many English-writing historians that translated kniaz'as princewere grossly mistaken. Raffensperger breaks with a well-established scholarly tradition and argues that the Slavic title of kniaz'should be rendered in English, at least in the case of Rus', byking. Accordingly, Rus' should be considered a kingdom. The argument is logically structured and beautifully condensed. It starts with a nine pages timeline that an impatient reader, as scholars usually are, might be tempted to skip. It would be a mistake, as the events listed in the timeline were selected with a purpose in mind: to convince the reader that Rus' was integrated in medieval Europe to a significant degree, up to the thirteenth-century Mongol invasion. The first chapter elaborates on this claim, arguing that Rus' was much more interconnected with medieval Western Europe than previously thought. Raffensperger's arguments are mainly grounded on the dynastic marriages and on the close religious ties between Rus' and the papacy. A reader familiar with his work will recognize here an abridged version, but fully meaningful, of the arguments he developed elsewhere.  The bulk of this short volume is nonetheless new, as five of the six chapters are dedicated to the problem of medieval titulature and to the most appropriate English translation of the Rusian title of kniaz'. The issue had been on Raffensperger's mind for more than a decade, judging from the conference papers on this topic mentioned in a footnote of his 2012 book. 
For a start, Raffensperger argues that the common scholarly translation of kniaz' derives from an early modern understanding of the Muscovite political system, developed during the first contacts between the English merchants and Russia. Hence, it is faulty and anachronistic to use this later meaning for a much earlier period, not to mention for a different society (Rus', not Russia). Raffensperger takes a step further and suggests that modern scholars preferred to use the title of duke or prince, as they somehow considered the rulers of Rus' inferior to the medieval Western kings. However, I suspect that most of the scholars that equated kniaz'with princedid not intend to convey a sense of inferiority, but simply went for the more generic term. Nevertheless, Raffensperger's call for a comprehensive re-examination of medieval titulature is most welcomed and the Scandinavian, Irish, Anglo-Saxon or Polish examples, chosen to illustrate how modern scholars usually simplified a much more complicated world of medieval titles, beef up his argument.
The core of Raffensperger's reasoning is laid out in the last three chapters of the volume. He starts by discussing the basic attributes of the Rus' kniazia in war-making, law-giving and tax-collecting, highlighting the similarities with other rulers elsewhere in medieval Europe. Next, he adds to the Rusian sources – Rusian not Russian, as Raffensperger likes to emphasise--the Latin, Old Norse, German and Greek ones. This comparative analysis of the medieval titles assumed by and ascribed to the rulers of Rus' ends conclusively: "the majority are similar, if not identical, to those used for rulers whose titles are translated into English as king" (65). Raffensperger rounds up his argument by briefly looking at how other medieval rulers, such as the Polish, Hungarian, Polovtsian and Byzantine ones, were viewed and titled in the Rusian sources. The book ends with a short epilogue, called Consequences and Resolution, which is once again a plea for restoring to the Rusian rulers their accurate medieval title, that of kings. To exemplify how this translation change will give us new insights into medieval Rus', Raffensperger goes back to the subject of dynastic marriages. The example he had chosen is that of Anna of Kiev, as he claims that historians might be able to understand better the underlying reasons of this Franco-Rusian dynastic marriage by placing Iaroslav of Kiev and Henry of France on an "equal plane due to their titulature" (78). Unfortunately, Raffensperger does not go further, into actually reinterpreting this marriage. One has the feeling that elevating Iaroslav's status from princely to kingly does not change much of Raffensperger's previous analysis of this marriage, an excellent one, from his 2012 book (when he simply called Iaroslav, more neutral, rulerof Rus'). 
Raffensperger's The Kingdom of Rus'is a brilliant little piece of scholarship, highly compelling in its polemical parts, but not equally persuasive when it comes to the book's main goal. Certainly, the titulature of medieval rulers was too often shorthanded by modern scholars and there is a need to look much more carefully into the distinctive meanings of various titles, from different regions and periods. However, to replace the translation of the Rusian title of kniaz'by kinginstead of prince,seems to cause more problems than it solves. Take for instance Raffensperger's main reason for calling for this change, which is to re-integrate medieval Rus' in a larger, interconnected, medieval Europe. We should leave aside for the moment the fact that, beside the marital ties, there is not much evidence for this interconnectivity. The issue here is that Raffensperger's medieval Europe seems to be far too homogenous for such an early period. Robert Bartlett convincingly argued that only in the twelfth and thirteenth centuries the diversity of local cultures and societies of medieval Europe was slowly replaced by an increasing uniformity.  There is something distressingly homogenizing in the way Raffensperger built his argument. Although he mentions the usual academic caveats about the complexity of medieval reality, he is more than once willing to simplify the picture, in order to support his contention. By approaching medieval kingship from a strictly functionalist viewpoint Raffensperger argues that "the basic functions of the kniazia in Rus' (ruler, military leader, lawgiver, and tax collector) were the same as for most rulers throughout medieval Europe, and the varying power relationships were similar" (43). Such a view disregards the laborious distinctions that medieval authors took pain to articulate. Certainly, a rex, a konungr, a kniaz', a regulus, a tsar, a kral, a velikii kniaz, a rí, akagan--and the catalogue of medieval titles could go on--were all more or less kings. The question seems to me, however, what kind of kingship the medieval rulers and their subjects had in mind when using these titles. For instance, what exactly was the difference Rusians made between their ruler, which they called kniaz', and an Old Testament king, which they called tsar? Or, to give the most obvious example, what set apart a velikii kniaz'froma kniaz'? Asserting that the former title was used "neither particularly frequently by chroniclers nor with any political consistency" (46) is a self-defeating argument, as the point of the whole book was that medieval titulatures do matter.
An important point in the book's line of reasoning is that medieval titles were assumed by a ruler or ascribed to one, in a deliberate manner. Raffensperger usually draws on this idea in order to take out of his way those titles that undermine his contention. Innocent IV's choice to addresses Alexander Nevsky as dux of Suzdal is explained as an attempt to convey a certain message in a specific (Baltic crusading) context. Similarly, the titles ascribed to the Rusian rulers by the Byzantines are considered most problematic due to their authors' self-proclaimed superiority and to their fondness for out-of-date terminology. To give just one more example, the non-royal title of senior Ruzorum used by Bruno of Querfurt, one of the few Latin authors that actually travelled to Rus', is explained as an "acceptable shorthand" (56) for someone whose focus was not titulature. However, Raffensperger fails to consider that not only the lesser titles are liable to such a critique, but also the aggrandizing ones. When the abbot Wilhelm referred to the Rusians rulers asreges, he did not correctly and knowingly recognize their status among European royalty. Instead he was designing an elaborate argument in favour of the repudiated queen of France, Ingeborg of Danemark, claiming that she was of extremely high birth, daughter and sister of kings.  The status and titles of medieval rulers were in the eyes and interests of those who wrote about them. For some authors, in some contexts, the rulers of Rus' were indeed kings--whatever they meant by that title--while for others they were definitely not.
This book has the great merit of revealing a critical scholarly problem: medieval titles are often translated routinely, following a long-established historiographical tradition. Raffensperger invites us to question these deeply rooted practices, to look for their implicit presumptions and to get rid of "the presentism of past generations" (77). The problem he accurately identifies and methodically exposes remains a crucial one for a better understanding of medieval Europe.
1. See mostly Christian Raffensperger, Reimagining Europe: Kievan Rus' in the Medieval World (Cambridge MA: Harvard University Press, 2012). On Evpraksia Vsevolodna's involvement in the Investiture Controversy, see Christian Raffensperger, "Agent of Change: Evpraksia Vsevolodovna between Emperor and Papacy," in Portraits of Medieval Eastern Europe, 900-1400, eds. Donald Ostrowski and Christian Raffensperger (Abingdon: Routledge, 2017), 178-184.
2. See Christian Raffensperger, Reimagining Europe, 195, n. 16.
3. See Christian Raffensperger, Reimagining Europe,94-97.
4. See Robert Bartlett, The Making of Europe: Conquest, Colonization and Cultural Change 950-1350 (London: Penguin, 1994).
5. Raffensperger argues that Bruno placed the Rusian ruler on equal foot with Henry II. However, in the case of the latter, the word senior does not refer to a title, but rather to express personal dependence (as in the case of St. Peter, also called senior). I found Wojciech Fałkowski's interpretation more convincing: "In this context, the term seniorreferred to a monarch or leader of undetermined status whom Bruno had met in person, but whose position in the broader, supranational hierarchy of power and majesty he was unable to grasp. The title lord and master of Ruthenia was an elegant measure employed to conceal the author's ignorance in the matter and his inability to verify the actual status of his host who was so generous in his aid to the missionaries," in "The Letter of Bruno of Querfurt to King Henry II," in Frühmittelalterliche Studien 43.1 (2009): 417-438.
6. See Anti Selart, Livonia, Rus' and the Baltic Crusades in the Thirteenth Century (Leiden, Brill, 2015), 29.