In the spring of 842, an assembly of clerics at Aachen discussed the deeds of Emperor Lothar I, who had recently fled the palace in the face of his brothers’ advancing armies. The clerics considered Lothar’s oath-breaking, his greed, and his lack of knowledge of how to govern the commonwealth (scientia gubernandi rem publicam), and they concluded that God had rightly given his kingdom to his brothers, Louis and Charles, since they were better men than he.

The character assassination of Lothar that the Frankish historian Nithard here compresses into a few lines at the beginning of Book IV of his »Histories« is unusual in its intensity, but as has been emphasised by historians such as Elina Screen, almost all the major contemporary narrative sources were hostile to this Carolingian ruler. In view of this hostility, and in the absence of any annals or chronicles that might present his view of matters, it is not surprising that Lothar has been relatively little studied; but this has left a ghostly vacancy at the heart of high Carolingian political history.

Now, however, in this slightly revised 2016 Bonn thesis, Maria Schäpers provides across 800 pages and nearly 5000 footnotes a painstaking and thorough study of the gesta Lotharii, from his birth c. 795 to his death in 855. Schäpers’ stated ambition in writing this book was to sharpen our view of Lothar and to gather as much relevant evidence as possible (p. 669). The outcome of this careful scholarship is an assessment very different from that peremptorily made by Nithard’s clerics at Aachen. Although a shorter book might have won a wider readership, historians with an interest in Carolingian Francia will be grateful for the expert sifting and assessment that Schäpers’ book offers.

The book is arranged chronologically. After a survey of the surviving sources, Chapter 2 assesses Lothar’s early years, from his childhood and education through to 830. A third chapter is devoted to 830–840, a decade marked by successive rebellions and reconciliations with his father Emperor Louis the Pious, and the fourth to the civil war with his brothers between 840 and 843. Chapter 5 then studies Lothar’s politics and rulership after the Treaty of Verdun through to his death in 855. A short Chapter 6 focuses on his entry into the monastic community of Prüm shortly before his death, and on the probably last-minute division of his kingdom between his three legitimate sons, before a short conclusion summarises the key discussions.

The Lothar I who emerges from this study is a somewhat tragic figure. As Schäpers notes in her conclusion, Lothar failed to fulfil the promises and expectations laid upon him in 817, when his father had marked him out as future emperor with pre-eminence over his brothers – but, she wonders, could he really ever have succeeded? Far from Nithard’s dastardly desperado, Schäpers’ Lothar is an honourable man placed in a nigh-impossible situation. Punished by Louis the Pious in 829 for complaining about a significant change in succession plans, he subsequently merely joined a rebellion that was already under way, and whose failure was not his fault. His rebellion in 833 was intended primarily to restore the pre-829 situation, and when this rebellion too began to lose steam, he released his father from imprisonment in 834 to protect his life. After 843, Schäpers argues, Lothar largely refrained from undermining his brothers’ kingdoms from within. Even after Verdun, he clung onto the dream of re-establishing the settlement that he had been promised in 817, but he hoped to do so without bloodshed, through peaceful and above-board means, for instance by having one of his bishops, Drogo of Metz, appointed as papal representative for Francia.

Perhaps the study underplays both Lothar’s strategic ruthlessness and his limitations as a strategist. His vindictive execution of the nun Gerberga, the sister of one of his aristocratic opponents, who he had drowned as a witch in 834, is glossed as a symbolic gesture against his enemies (p. 291), which may not have been how Gerberga or her family would have understood it. His abandoning of Pippin II to the mercies of King Charles the Bald in 843 is presented as simply an unfortunate inability to protect his cousin any longer, rather than a cynical disposal of a no-longer useful ally. And the argument that Lothar held no realm-wide synods because he saw no particular need for them is in a way merely a restatement in positive terms of Anton’s suggestion that Lothar refused or was unable to think in terms of regnal episcopacies.

Yet these interpretations are welcome in their challenge to historians not simply to repeat the calumnies of Nithard and others when considering this maligned heir of Charlemagne, whose chief deficiency may really have been the ill-fortune of not having a favourable set of annals or histories to represent his actions to posterity. Maria Schäpers brings out clearly the difficulty of Lothar’s position, but also its strengths and the ruler’s resilience in the face of repeated setbacks. Throughout the book, Schäpers offers nuance and insight, for instance in her deft portrayal of Empress Irmingard’s influence and agency, in tracking Lothar’s preparations for his son Louis II (another historiographically neglected ruler) to take on the imperial mantle, and in analysing the emperor’s shifting relations with the papacy. This is a careful and detailed study, well anchored in the evidence, that one hopes will succeed in its aim of fostering and enabling future research on this important figure.