This chapter examines the concept of heresy through the growth of papal decretals, canon law and conciliar legislation during the High and Late Middle Ages (eleventh to fifteenth centuries). It explores the growth of medieval heresy during a period of burgeoning papal power and examines how popes both reacted to and constructed ideas of heresy and heretics.

This chapter examines the reciprocal accusations of heresy between the Byzantine East and Latin West: such accusations were only sporadically made during the first millennium but increased exponentially from the twelfth century onwards on the Byzantine side and, to a lesser extent, from the thirteenth century on the Latin side (where they were generally subsumed under the accusation of schism or ‘disobedience’). The notions of ‘heretic’ and ‘schismatic’, which ought to be distinct and precisely defined according to canon law, increasingly overlapped within the polemical discourse and were collectively applied to the opposite population, in a process of construction of religious otherness.

This chapter examines rituals which took place after childbirth, uncovering evidence of baptisms, circumcisions, and even churching ceremonies that were held in domestic spaces. It suggests that a range of ceremonies we would now associate with public places of worship were frequently located in domestic spaces. It moves beyond studies which have argued that domestic baptism primarily took place in the home out of necessity, demonstrating that elective domestic baptism was more commonplace than has previously been acknowledged. Domestic ceremonies could also take place in networks of homes, being accommodated not in the family home, but in the home of a midwife, rabbi, or lay co-religionist. These ceremonies, and associated processions from the home to the place of public worship, marked the symbolic ending of the lying-in period, the departure of the mother from the home, and the welcoming of the child into the religious community. They emphasise the significance of the home as a setting of communal sociability and religious practice, and provide an important opportunity to consider the central place of the individual household within its congregation.

Two networks transformed the early modern world. The first was the Iberian network of discoverers and conquerors that helped usher in an age of European world domination and colonialism. The second was facilitated by a new technology, printing, which helped unleash the huge religious and political disruption we know as the Reformation. What Niall Ferguson describes as a “religious virus that came to be known as Protestantism” disrupted an ancient ecclesiastical hierarchy, fractured into many pieces Europe’s Catholic Christianity, and ushered in a long era of violent conflict. This chapter investigates religious networks within the Lutheran, Reformed, and Radical wings of the Reformation and highlights the formation, evolution, suppression, and ultimate survival of the Jesuit Order as a classic transnational network within Catholic Christianity.

The documentation related to inquisitorial practice included trial transcripts, consultations, sentences, manuals and accounts. But while this documentation was a key ingredient in inquisition’s power, the relationship between these sources and our knowledge of medieval heresy is complex.

This chapter defines the theoretical terms – networks, nodes, and nuclei – explains the choice of dates between two revolutions in communication (print and the internet), and gives some concrete historical examples of the tangible benefits of looking at the history of Christianity through transnational flows and networks. This approach allows us to cross national and denominational boundaries and borders and to think more deeply about the underlying social and cultural conditions promoting or resisting adaptation and change. It also enables us to explore the crossroads or junction boxes where religious personnel and ideas encountered different traditions and from which something new and dynamic emerged.

This chapter examines religious practices which took place in the home immediately after death: from the laying out, washing, and watching of the body, and domestic gatherings such as ‘wakes’, to the removal of the body from the home, its transfer to a burial place, and the attendant rituals associated with the disposal of the body and mourning for the deceased. It also identifies evidence of cases where the home itself was used as the location for the funeral rites. While the watching and disposal of the body necessarily catered to social and biological needs, religious aspects were closely intertwined with many seemingly practical decisions. The washing and laying out of the body, for example, would generally be performed by members of the parish or local religious community. This chapter makes use of wills, personal writing, burial records, and congregational records which provide an insight into the relationships between individual households and a wider congregation, including its designated burial ground. It argues that the home facilitated acts of communal religion in the hours and days after death, as it became the setting for gatherings and acts of charity to the body.

Unlike many other forms of ‘heresy’, Manichaeism is not a polemical construct but an independent and organised church within the Christian tradition originating in Mesopotamia and Iran in the third century CE. It had its own heresiology against other communities such as the western Catholic-Orthodox church, identifying key points of difference and deviance from the ‘faithful and true Christianity’ of Manichaean doctrine and practice.

Most religious traditions and movements have majorities of women, but most are led by men and are based on deeply embedded patriarchal assumptions. That underlying reality is played out in multiple different Christian traditions and shapes the subsequent contests for power, representation, and influence. This chapter is animated by a primary question from which other questions naturally flow: What are the characteristics of the religious networks constructed by women and to what extent do they function differently from those built largely by men? In attempting to answer that question, I identify five different kinds of networks representing different varieties of female leadership and participation. It is important to state that this typology should not be read as either an ascension or declension narrative about women’s agency and the role of patriarchy in shaping that agency.