In the study of family and kinship, siblings and their relationships are a neglected subject, compared with parents and children, or alliance through marriage. Justine Audebrand’s excellent new book is thus very welcome. She covers the High Middle Ages in a comparative study centred on Frankish, Germanic and English sources. These are areas with different historiographies on kinship and family, and different patterns of surviving source material both in quantity and genres. Lacking the English gender-neutral term »sibling/s«, she prefers »adelphe« and »adelphie« for the siblings and sibling groups of brothers and sisters which are her subject. This is a first sign of a sensitivity to gender which is one of the book’s strengths. So too is its wide-ranging analysis of the full gamut of primary sources – narrative, hagiographical, diplomatic, literary, material – which she rightly considers essential. The result is an important contribution to the historiography.

The book begins with a discussion of terminology and the definition of the group, both internally and externally. Frater/soror are compared with germanus/a, with the latter carrying a heavier freight of blood and biological connection and in full decline in the sources by the tenth century. Like so much in this book, the discussion of change and continuity is carefully nuanced. The size and boundaries of the group, inclusions and exclusions, cover aspects such as half-siblings, adoption – rare almost to the point of absence – and fosterage. Sibling relations are horizontal in nature and potentially egalitarian, a fact of great importance including for the power of this bond as a wider social metaphor, not least for spiritual kinship. However, Audebrand also stresses the internal hierarchies of e.g., birth order and age. This latter, changing with the birth of new children, is a first sign of the constant re-orderings of the sibling group, of dynamic reorganisations, which recur throughout the book.

The bulk of the book deals with this bond in action, with practical kinship as opposed to genealogical reconstitution. The next four chapters consider the formation of the bond and circumstances of its affirmation and expression. One centres on infancy to adulthood, discussing the contribution of rearing to the bond’s working and strength. One chapter on power considers its exercise by and division within the sibling group, concerned mostly with royal families and with some recurring patterns: of king and brother-bishops; king and sister abbess; king and his brother/successor – peculiarly English, and the queen and her brothers. A third chapter deals with the management of land and patrimony, stressed here as often a joint sibling exercise – though not in England – which can divide, but more generally reinforces collaboration. The fourth chapter considers intimacy, solidarity, counsel, and the stress on sibling affection in the sources. The last chapters deal with war, widowhood and death, circumstances which threaten the sibling bond and group with rupture but which also redraw and reshape it.

Throughout the book, attention is given to gender differences and similarities, to class/status – especially the differences between royal families on which we have so much evidence and other families – and to chronological and geographical specificities. Audebrand is not afraid to make broad generalizations, but always hedges and complicates them. The gendered differences between brothers and sisters are highlighted. But so too is the need to distinguish among sisters: between the married and unmarried, and at different stages of the lifecycle, e.g., in widowhood, where the bond is often reactivated and its egalitarian potential underscored. But even in widowhood we must distinguish between those who are still of marriageable age and those beyond it. Class and status divide the well-documented royal families from other groups, and clerical status is given constant attention. Counsel among siblings, e.g., is gendered: brothers explain and sisters receive; the counsel of sisters to brothers is care and support, while that among brothers is one of equals. But when the brother is, as so often in these sources, a cleric, even a bishop, the clerical hierarchies emphasize the gender inequality and can disrupt the equality of brothers – except in the specific and recurring case of king and brother-bishop.

The book abounds in insights. The pattern of the Ottonian family and its rule, drawing in sisters as well as brothers, is underscored – though here the growing significance of the conjugal couple may, paradoxically, enhance the role of some sisters as substitute wives of celibate brothers. The Carolingian strife between brothers produced particularly strong discursive emphasis on the fraternal bond and its importance. The patchiness and paucity of surviving sources mean that England cannot always provide comparisons. But apparent English differences, like the importance of strong claims by brothers on inheritance or the general lack of the king plus brother-bishop there, demonstrate precisely the value of this comparative approach, and underline the exceptions, e.g., King Eadberht and his brother Archbishop Ecgberht in eighth‑century Northumbria. Familiar figures appear in new lights. Queen Eadburh, widow of King Beorhtric and infamous in late ninth‑century English sources, was a widow with no brother to support her. But statements about England need to be read in the context of source patterns and poverty. Brothers of queens do not appear much before the tenth century; perhaps, though the gap in sources usable for genealogical research in the eighth and ninth centuries urges caution. The scarcity of private charters in England vis‑à‑vis the wealth of those from Cluny or St Gall means that many statistics should have a similar health warning.

Overall the book emphasizes the strength of the sibling bond, both as an ideal, especially in clerically-authored sources, but also in practice. By contrast, the ensuing period emphasized the couple and the vertical bonds of the conjugal family, a shift already apparent by the tenth century. The author herself presents evidence of tensions within the sibling group. She is aware of the extent to which sources committed to this ideal hide these, and of the impact of changes in source material from the tenth century onwards. But the overwhelming direction of the evidence is persuasive. The wide source base and comparative nature of this study, which are its fundamental strengths, mean that her conclusions will need to be taken very seriously in future work. Some are less convincing than others, inevitable in such a wide-ranging study. But this book, which opens up a wealth of questions and lines of enquiry, is a must read for all interested in kinship and family in the Middle Ages.