With Fosterage in Medieval Ireland: An Emotional History, Thomas O'Donnell has written the first book-length work on fosterage in the Middle Ages. This is an accomplishment to be celebrated, and it follows in the footsteps of other first book-length works, such as Adam Kosto's Hostages in the Middle Ages (2012), Carolyne Larrington's Brothers and Sisters in Medieval European Literature (2015), and John Boswell's The Kindness of Strangers: The Abandonment of Children in Western Europe from Late Antiquity to the Renaissance (1988). Additionally, O'Donnell's book focuses on children, which puts him in company with authors such as Nicholas Orme, whose Medieval Children (2001), along with Shulamith Shahar's Childhood in the Middle Ages (1990) and Barbara Hanawalt's Growing up in Medieval London (1993), kick-started the recent uptick in investigations of childhood in the medieval period. And O'Donnell's book is also about emotions, and how emotion is displayed in medieval Irish texts about constructed/fictive kinship relationships, which clearly draws on Barbara Rosenwein's Emotional Communities in the Early Middle Ages (2006).

While O'Donnell has a clear line of influences, he makes the subject his own and covers secular, religious, and bestial fosterage. Fosterage in medieval Ireland was a ubiquitous social and legal institution in which children, either as infants or about the age of seven, were sent to another family to be brought up. Fostered children were generally the children of noblemen, and could be fostered either up or down the social scale, as a way of reinforcing, maintaining, or creating political bonds. It was expected (and legislated) that fostered children be instructed according to their status, so there was also an educational aspect to the practice.

There are dozens of Old and Middle Irish texts that fleetingly discuss fosterage. The practice was not explained in narrative texts, in much the same way that relationships between parents and natal children are assumed. O'Donnell is the first to analyze these foster relationships and their affective ties in depth. His goal is to create “not the lived reality of fosterage but the social expectations of the bond” (23). To do so, he asks how that bond was created and what its limitations were. So, for instance, the first two chapters take as their central case study Cú Chulainn, the Ulster hero associated with Táin Bó Cúailnge (The Táin), and the network of fosterage ties that go from his birth to his death. Cú Chulainn, in several birth tales, is assigned multiple foster fathers, which many critics have seen as a marker of his importance: the more important the child is, the more instruction he needs from a variety of instructors (foster fathers). O'Donnell, though, argues that Cú Chulainn's multiple—or in his more elegant term, “corporate”—fosterage (42) is highly unusual and that Cú Chulainn's relationship with his foster fathers should not be considered separately from his relationship with the other members of his foster family, such as foster mothers and siblings. The affective bonds between foster fathers and their foster children are the core of the first chapter, followed by bonds between foster siblings in the second chapter. In both chapters, the question of identity is central: Who gets to be the foster father? Which foster sibling is identified as a proper sibling, and how is that determination made? The foster sibling relationship relies upon the presence of a foster mother in common, notably Scathach, who fosters Cú Chulainn and his foster brothers and trains them in arms. O'Donnell concentrates on the combat between Cú Chulainn and his beloved foster brother Fer Diad, an episode that is one of the emotional cores of Táin Bó Cúailnge. Forced to fight, Cú Chulainn laments the circumstances of this battle; when he finally kills Fer Diad, he weeps and places the reason for his sorrow squarely on Fer Diad's betrayal of their sibling bond. O'Donnell counters the recent trend in scholarship to see the relationship between Cú Chulainn and Fer Diad as being at the very least homoerotic by carefully establishing their relationship as foster brothers and illustrating that Cú Chulainn's anger and remorse at Fer Diad's death are entirely appropriate for the loss of the relationship with his brother.

The remainder of the book centers on saints. The third chapter investigates fosterage terminology, illustrating how it can be used to define and create emotional bonds in nontraditional familial settings such as Finn Mac Cumhaill's warrior bands and monasteries. The fourth chapter is an investigation of fosterage by and of saints. Several Irish saints are depicted as fostering Jesus, and I was particularly struck by O'Donnell's discussion of the shift in emphasis from education—the Holy Spirit instructing Colm Cille on mysteries of scripture, for example—to consolation—Adomnán holding the Christ child in his lap and receiving solace. There is a corresponding shift from attention to the divinity of Jesus to the emotional benefits that such a fosterage relationship had (149–50). O'Donnell also turns his attention to male saints who fostered children by miraculously nursing them, which turns fosterage into a misogynistic tool, removing women completely and reinforcing the masculine world view of the medieval church (152–56). In his final chapter, O'Donnell turns his attention to wolves who fostered children, one of whom is Saint Ailbe.

O'Donnell's work is groundbreaking and will be the study to reference when thinking about fosterage in the near future. In fact, I found myself wishing that O'Donnell had been able to include a larger discussion of fosterage beyond Ireland, as it is an institution that was practiced throughout Europe. And I did wonder why, in the second chapter about Cú Chulainn and his relationship with foster fathers, O'Donnell did not also discuss Cú Chulainn himself as a foster father. In “Mesca Ulad,” Conchobor has given his son Furbaide to Cú Chulainn to foster, and the tale shows Cú Chulainn desperately trying to assuage the little boy's (pretended) grief over an incident, certainly highlighting the affective bonds between foster father and foster son. But this just gives O'Donnell more to work with in the future, and I very much look forward to seeing that work.