The book is devoted to the relationships between Nicene and Homoian Christianities in the context of broader religious and social changes in post-Roman societies from the end of the fourth to the seventh century. The main analytical and interpretative tools used in this study are religious conversion and ecclesiastical competition. It examines sources discussing Nicene–Homoian encounters in Vandal Africa, Gothic and Lombard Italy, Gaul, and Hispania – regions where the polities of the Goths, Suevi, Burgundians, and Franks emerged. It explores the extent to which these encounters were shaped by various religious policies and political decisions rooted in narratives of conversion and confessional rivalry. Through this analysis, the aim is to offer a nuanced interpretation of how Christians in the successor kingdoms handled religious dissent and how these actions manifested in social practices.

Chapter 7 is focused on conversions in a family context, collecting and comparing evidence from Gaul, Hispania, and Italy. The starting point is an examination of the secular and ecclesiastical rules governing interdenominational marriages and the differences in church loyalty between parents and children. Then the conclusions drawn from the normative sources are connected with what we know about the social reality of ‘mixed’ families. Given the nature of our evidence, the chapter focuses primarily on marriages and conversions in royal contexts. It analyses the examples from the ruling house of Suevi, marriages in the Burgundian family of Gibichungs, and marriages between the Visigothic and Frankish ruling families.

Chapter 6 analyses how the re-emergence of Homoianism among the Visigoths, Vandals, and Suevi was interpreted in the Nicene church in Gaul and Spain and what this reception reveals about Nicene–Homoian relations in the region in the fifth century. It also examines the evidence for the development of the Homoian Church and the increase in the number of Homoians.

Chapter 8 is devoted to the ways in which some Nicene bishops attempted to persuade kings to convert, illustrated by the examples of Avitus of Vienne and Leander of Seville, and to conversion as a political project and as a theme of the ideology and theology of kingship in late sixth-century Visigothic Hispania. Conversion and royal rule in Gaul and Hispania were also linked to another important phenomenon: the cult of saints. Thus, in this chapter three cults that played an important role in Nicene–Homoian relations are analysed: the cults of the apostle Peter in Burgundy, of Martin of Tours in Gaul, and of Eulalia of Mérida in Visigothic Hispania.