History Extra Podcast: How Christianity Came to Dominate the Roman World

Date: August 28, 2025
Host: Danny Bird (for Immediate Media)
Guest: Prof. Alice Roberts (Anatomist, biological anthropologist, author and broadcaster)
Main Theme: Exploring the transformation of the Roman world through the spread of Christianity, challenging common myths, and tracing the interplay of religion, politics, and culture from the late Roman Empire to modern Christianity.

Episode Overview

This episode features a wide-ranging conversation between Danny Bird and Professor Alice Roberts, focusing on her new book, The Fall of the Roman Empire and the Rise of Christianity. Roberts unpacks how Christianity spread across the late Roman world, not as a purely grassroots movement of the poor, but as a strategic phenomenon deeply intertwined with urban elites, politics, and existing Roman structures. The discussion covers archaeological evidence, misconceptions about the early church, the political savvy of bishops and saints, and the enduring legacy of Roman traditions in the Christian faith.

Key Discussion Points & Insights

Alice Roberts’ Fascination with the Period

[02:36]

• Prof. Roberts explains her interest in the post-Roman period, focusing on the paucity of historical records in Britain which pushes historians to rely on archaeology and material culture.
  • Her initial intrigue stemmed from excavating cliffside burials in Wales with early Christian markers, prompting broader questions: How did Christianity reach remote areas so early, and who was responsible for its spread?
  • “All the way through the book I’ve tried to get away from abstractions... It’s all about people. So who was spreading it and why?” (Alice Roberts, 05:13)

Challenging the Myths: Christianity and the Elite

[06:11]

• Early Christianity is commonly thought of as a refuge for the oppressed, but evidence suggests rapid adoption among urban elites.
  • Example: St. Paul immediately seeks the patronage of the Governor of Cyprus.
  • “He’s not going out preaching to people who have no means. He’s going straight to people who have very high up jobs.” (Alice Roberts, 06:49)
  • Adoption of Roman patronage traditions—Paul takes on the Roman name “Paulus” from his patron.

Writing and Research Approach

[07:55]

• Roberts structured the book as a journey through the Empire—Wales, France, Alexandria, Constantinople—grounding her research in physical geography and material evidence.
  • “I sometimes feel as though I’m stepping on a hypocaust... sometimes the floor wasn’t there, and I’m stepping from pile to pile... That’s when I really need my colleagues.” (Alice Roberts, 09:49)
  • Importance of collaboration and consulting specialists due to the vastness of the subject.

The Complexity of Constantine’s Conversion

[11:06]

• Roberts delves into the myth of Constantine as a devout Christian emperor, revealing inconsistencies in both his policies and the symbols on contemporary coinage.
  • Constantine’s “Christian” iconography such as the Chi-Rho was used sparingly and had pre-Christian meanings.
  • “I was absolutely gobsmacked to find out that the Chi-Rho has a pre-Christian origin and a pre-Christian life as a symbol.” (Alice Roberts, 14:56)
  • Eusebius’ biography of Constantine may be more a product of ecclesiastical agenda than fact.

Was Christianity ‘Pre-Adapted’ to Empire?

[16:30]

• The religion’s structural compatibility with Roman systems facilitated its spread; urban, literate, philosophical, and elite-driven.
  • “A successful meme has to mean something in the culture it emerges in... And absolutely... it becomes more and more Roman.” (Alice Roberts, 16:45)
  • Tertullian and Bishop Ambrose are cited as marshaling Roman identity to support Christianity’s legitimacy.

The Church as a Proto-Empire

[20:03]

• Early Christian communities operated like Roman guilds or collegia, supporting members through mutual aid; as elites joined, the Church fused with local and imperial administration.
  • As city administrators became bishops, the church’s structure paralleled and ultimately outlasted imperial government.
  • “The church is just completely fused with that... Basically happening under a Christian aegis, it’s the bishops that are running the cities.” (Alice Roberts, 23:17)
  • Elite Roman families maintained status throughout invasions by shifting into ecclesiastical authority.

Enduring Romaness in Modern Christianity

[26:56]

• Rituals, hierarchy, and even colors like imperial purple persist in today’s Church.
  • Roman festivals and funerary customs—like Parentalia—were absorbed into Christian practices and remain visible in modern Orthodox and Catholic traditions.
  • “People’s rituals carry on. It’s very interesting. I’m writing another book about that.” (Alice Roberts, 29:29)

Christian Theology: Original or Derivative?

[31:11]

• Early Christianity was not a radical break but a synthesis of Jewish tradition, Hellenistic philosophy, and Roman values.
  • Christianity’s supposed originality, especially in charity, is overplayed—it built upon existing practices like Roman euergetism (philanthropy).
  • “It’s patent nonsense [that Christianity invented charity]... society wouldn’t have worked if it hadn’t been [valued].” (Alice Roberts, 34:11)

Unity, Factions, and Survivability

[35:53]

• The Church’s capacity to enforce doctrinal conformity (e.g., Council of Nicaea) mirrored and replaced the imperium’s expectation of loyalty; this unity became a vital tool in an era of instability.
  • “That rigidity... that need to adhere to one thing, that is binding people together. It’s very political.” (Alice Roberts, 36:31)

Bishops, Saints & Missionaries: Not Humble, but Political

[37:15]

• The narrative of ascetic saints traveling to remote places often obscures their real role as power brokers, closely connected to elite societies and rulers.
  • Missionaries and bishops often reinforced power structures—sometimes literally arriving with troops.
  • “It’s all about nobility, it’s all about the connectedness of these very, very noble families...” (Alice Roberts, 38:11)

The “Fall” as a Rebrand – Not a Collapse

[39:39]

• Roberts’ central thesis: the so-called “fall” of Rome is better viewed as a transformation and rebranding, with ecclesiastical structures inheriting and perpetuating Roman administrative, educational, and cultural traditions.
  • “If the empire is the whole system of administration and education and the hierarchy of Roman society, it’s there all the way through.” (Alice Roberts, 40:09)

Objectivity and the Author’s Perspective

[40:50]

• Roberts reflects on her position as a prominent atheist and former President of Humanists UK, stressing an attempt at objectivity and cultural analysis rather than polemic.
  • “I hope it didn’t [influence the book] because I’m trying to approach this history as objectively as possible...” (Alice Roberts, 40:50)
  • She seeks to understand the motivations and appeal behind Christianity’s spread, fascinated by its evolution rather than invested in its ideology.

Notable Quotes & Memorable Moments

• “Rather than saying Christianity spread across Europe, it’s all about people. So who was spreading it and why?” – Alice Roberts, [05:13]
• “You’re looking at a system where the Roman administration is basically fused with Christianity, or maybe infused with Christianity is a better way of describing it.” – Alice Roberts, [24:54]
• “I was absolutely gobsmacked to find out that the Chi-Rho has a pre-Christian origin and a pre-Christian life as a symbol.” – Alice Roberts, [14:56]
• “The church is just completely fused with that [Roman elite administration]... bishops are running the cities.” – Alice Roberts, [23:17]
• “It’s all about nobility, it’s all about the connectedness of these very, very noble families... some of them are bishops and some of them are kings.” – Alice Roberts, [38:11]
• “I absolutely do [think it’s time we stop talking about the fall of Rome and start seeing it as a rebrand]... the hierarchy of Roman society is there all the way through.” – Alice Roberts, [39:41]
• “I sometimes feel as though I’m stepping on a hypocaust... That’s when I really need my colleagues.” – Alice Roberts (on research approach), [09:49]

Timestamps for Important Segments

• [02:36] Origins of Alice Roberts’ interest; importance of archaeology
• [06:11] Early Christianity as an elite, urban phenomenon
• [09:49] Challenges of research across disciplines; metaphor of the hypocaust
• [11:06] Constantine’s conversion and its mythologization
• [14:56] The pre-Christian origins of the Chi-Rho symbol
• [16:30] Christianity’s structural adaptation to Roman society
• [20:03] The early Church as a guild/collegium; elites and administration
• [23:17] Bishops as city administrators; continuity of elite families post-Empire
• [26:56] Roman festival customs in modern Christian ritual
• [31:11] Continuity of charity and social care; Christian and Roman values
• [35:53] Rigidity and unity in early Christianity; political utility
• [37:15] Bishops, saints, and missionaries as elite power brokers
• [39:39] “Rebranding” Rome: survival of institutional frameworks
• [40:50] Alice Roberts’ perspective as an atheist and cultural historian

Conclusion

This episode presents a nuanced and fresh perspective on a much-misunderstood period: the transformation of the Roman world through Christianity. Roberts and Bird dissect myths surrounding early Christianity, emphasizing its roots in Roman society and administration, the adaptability and political intelligence of its leaders, and the persistence of Roman cultural forms in Christian practice to this day. The episode offers a rich, detailed exploration suited to listeners eager to challenge received wisdom and deepen their understanding of the ancient world's legacies.

Recommended for: Anyone interested in late antiquity, church history, cultural transitions, or the enduring influence of Rome.