When we think of the Church in Late Antiquity and the Early Middle Ages, we tend to picture a world dominated by bishops—rule-makers, patrons, saints, and political actors. This bishop-centric vision has long shaped our understanding of ecclesiastical institutions in sixth- and seventh-century Iberia, my area of specialism. But what if we shifted our gaze? What if, instead of focusing on the named elites, we considered the unnamed and enslaved individuals who laboured, travelled, and mediated on behalf of the Church? This was the direction in which I took my research during my time as a guest researcher at the BCDSS in late 2024. Now, around a year later, I’d like to share some thoughts on the work that I did in Bonn.
As a result of reading around the topic of social network analysis, I became increasingly interested in the role of intermediaries—individuals who occupied positions between the powerful and the powerless—in shaping the churches of Visigothic Iberia. These figures often remain unnamed in the sources and, as minor clergy or enslaved individuals, they were tied into dependent relationships with bishops, on whom they relied on for appointment, salaries, promotion, or – in the case of the enslaved – potential manumission. Despite their subordinate positions, the actions of these people were crucial to the functioning and expansion of the Church in Iberia and beyond.
Isidore of Seville (d. 636), a towering intellectual figure of the period most well-known for writing the Etymologies, a monumental work of reference that became one of the most widely-copied texts of the Middle Ages, is a telling example. In his correspondence with Bishop Braulio of Zaragoza, Isidore frequently mentions the intermediaries who carried letters between them. Some of these people were clerics, others may have been enslaved as in the case of the puer who carried a Letter B from Isidore to Braulio. Another letter refers to unnamed “servants” – potentially enslaved individuals – who were involved in the misfiling of correspondence (Letter III).
Interestingly, Braulio does not mention couriers or other intermediaries in his letters, suggesting variation in epistolary practice and perhaps differing attitudes toward intermediaries. Nonetheless, although Isidore refers to these messengers, apart from a cleric called Maurentiu (Letter A), he did not name them.
In order to dig into this further, during my time in Bonn, I learnt how to conduct social network analysis. I thought it could be an interesting means of identifying and analysing ecclesiastical intermediaries on a system-wide basis. I began by looking at Braulio’s collection of 44 letters, the largest to survive from Visigothic Iberia. The first image is one of my first efforts at making a social network visualisation of Braulio’s letters (don’t look too closely – it was a start, if not a particularly effective one). Note the correspondence between Braulio and Isidore, represented by the thick line at the bottom of the diagram. This reflects the fact that the seven letters exchanged between Braulio and Isidore were the most between any pair of individuals in the corpus (hence the thicker line).
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But when I reflected on what the thick line between Braulio and Isidore actually meant and went back to re-read the letters, I realised that the visualisation somewhat misrepresented what was going on. It ignored the intermediaries. So, I made this little diagram to represent the individual letters and the role of the letter carriers and other people mentioned in process.
The multiple thin lines don’t necessarily give us a more “realistic” representation of the correspondence than the thicker line that had been bothering me, but it did enable me to put the intermediaries into the picture. It also helped me to realise that alongside the attested messengers there must have been other individuals who carried the other letters between Braulio and Isidore but who were not mentioned (designated with “anon.” on the image). This is not to say that the seven Braulio-Isidore letters were carried by seven different people, because it is entirely possible that one messenger could carry multiple letters or work over an extended period. Nonetheless, this did give me a better visual sense of where the letter carriers who had been ignored by Braulio-Isidore came into the picture.
It also got me thinking about other intermediaries between bishops. Beyond letters, church councils offer another window into the question of intermediaries in sixth- and seventh-century Iberia. Over thirty councils were held in this period. They were central to ecclesiastical governance, yet attendance was patchy. Bishops often failed to appear, with illness, distance, or political instability likely factors in no-shows. In such cases, bishops could send deputies—presbyters, archpresbyters, abbots, archdeacons, or deacons – to act in their place. These deputies, though lower in rank, played a vital role in connecting bishoprics across the kingdom, like the letter carriers who connected Braulio and Isidore.
Over 10% of those who signed up (“subscribed”) to the records of church councils in the Visigothic period in Iberia were made by such deputies. The mobility of these intermediaries was essential to the cohesion of the Church. They travelled between dioceses, carried information, and facilitated decision-making. Their presence, though often obscured in the sources, helped to make the Church function as a network rather than a collection of isolated nodes.
Take Braulio again. He attended several councils: the Fourth, Fifth and Sixth councils of Toledo, which were held in 633, 636 and 638 respectively. These councils were moments at which the bishops could connect and their subscription lists are a snapshot of who attended.
The following network diagram is derived from the subscription list of the Fourth Council of Toledo in 633, a major “national council”, which was held in 633 and presided over by Bralio’s correspondent, Isidore. Braulio is at the centre, with his connections to the bishops who attended the council represented by the different lines.
But several bishops sent deputies rather than attending. For example, the presbyter Centaurus represented bishop Fidentius of Tucci, subscribing sixty-third on the list.
Looking closely at the edge of the diagram, it is possible to see that Braulio’s connections to those bishops who did not attend IV Toledo were mediated by a range of subordinate clergy, in addition to Centaurus:
Renatus the archpresbyter subscribed for Ermulfus, bishop of Conimbriga;
Marcus the presbyter subscribed for David of Auria;
John the presbyter subscribed for Severus of Barcelona;
Domarius the archdeacon subscribed for Carterius of Arcauica;
Stephanus the archdeacon subscribed for Genesius of Magalona;
Domnellus the archdeacon subscribed for Sollemus of Carcassone.
Of course, the subscription lists are simply a snapshot and cannot tell us anything about the quality of the connection between the people who attended the council – it simply indicates that they were in the same place at the same time. Similarly, it is entirely possible that there were other points of connection between Braulio and the other bishops (including those who did not attend the council). Like the letters mentioned earlier.
As I researched this topic further while at the BCDSS, I moved beyond Braulio and began to explore connectivity on a system-wide basis, looking at subscriptions throughout the period and modelling connectivity, including the integrative role of intermediaries, on a system-wide basis. There is insufficient space in this short blog post to say much more, but the following network visualisation moves us beyond a snapshot of an individual council to zoom in on the connections between the general Third Council of Toledo, held in 589, and some of the smaller councils that followed it.
When viewed from a network perspective, bishops’ deputies played a pivotal role in tying together the disparate bishoprics of Iberia, a topic that I will come back to in future.
Thinking with networks and generating the visualisations has helped me to see the individuals who carried letters between Braulio and Isidore and those who represented their bishops at councils not as peripheral but as central. Ultimately, by focusing on intermediaries we gain a richer, more textured understanding of how Iberian churchmen were connected to one another. These individuals were not mere functionaries; they were agents of connection, transmission, and transformation, and were pivotal to bringing the Church into being in Visigothic Iberia.
Note: my research was funded by the Leverhulme Trust as part of an International Fellowship. Further details of my project, The Unnamed, can be found here: https://makingdigitalhistory.co.uk/network/the-unnamed-slavery-and-the-making-of-the-church-in-late-antique-iberia/.
Network diagrams were generated using Gephi, an open-source network analysis and visualization software package (https://gephi.org/).
