Sunday School Review: Basic Church History: Nicaea through the Middle Ages, Part 10

The fall of the Roman Empire in the West marked not the end of civilization, but its transformation. What emerged in the ruins of Roman authority was a Europe deeply influenced by the church, which became the unifying force in a fractured world. Amid invasions, migrations, and cultural upheaval, the church took on the role of preserving order, spreading faith, and building a new foundation for European society. This era of transformation laid the groundwork for what we now call the Middle Ages and profoundly shaped the spiritual, cultural, and political trajectory of the West.

If you’re new here and missed last week's review, you can find it here.

The Pope Continues His Rise

As the Western Roman Empire collapsed, the bishop of Rome—later known as the pope—assumed an increasingly central role in both spiritual and political affairs. With no central imperial authority, the church became the primary institution capable of uniting the diverse and often warring peoples of Europe. The papacy, beginning with leaders like Pope Leo the Great, positioned itself as the successor to Roman authority, offering stability and guidance in a tumultuous age.

By the sixth century, the pope’s influence extended far beyond Rome. Papal diplomacy, theology, and leadership defined the Western church’s character, with the bishop of Rome increasingly recognized as the spiritual leader of Western Christendom. The concept of the pope as the successor of Peter, entrusted with the keys to the kingdom of heaven (Matthew 16:19), became central to this rising influence.

The Conversion of the Barbarians

As the Roman Empire fractured, Germanic tribes established kingdoms within its former borders. These tribes—Goths, Vandals, Lombards, and others—were largely pagan when they entered Roman lands but were often exposed to Christianity through their interactions with Roman culture. Many of these groups initially adopted Arian Christianity, a version of the faith that denied the full divinity of Christ, likely because it had been brought to them by Arian missionaries like Ulfilas, who evangelized the Goths in the fourth century.

While Arian Christianity represented a significant step toward integrating the tribes into the Christian world, it also created theological divisions with the Nicene (Catholic) church. The gradual conversion of these tribes to Nicene Christianity often came through political alliances, missionary efforts, and the influence of Roman clergy.

The History and Conversion of the Franks

Among the Germanic tribes, the Franks played a particularly significant role in the transformation of Europe. Unlike many of their contemporaries, the Franks embraced Nicene Christianity directly, a decision that would have far-reaching consequences for the development of Western Christendom.

The turning point came with the baptism of Clovis, the Frankish king, in 496 AD. Clovis, the founder of the Merovingian dynasty, reportedly converted to Christianity after a victory in battle, attributing his success to the intervention of the Christian God. His baptism by the bishop of Reims marked the Franks’ official acceptance of Nicene Christianity and forged a strong alliance between the Frankish monarchy and the Roman Church.

The Franks’ conversion was instrumental in establishing the Catholic faith as the dominant form of Christianity in Western Europe. As their power grew, they became protectors of the church, a role that would culminate centuries later in the crowning of Charlemagne as Holy Roman Emperor.

The Conversion of the British Isles

The British Isles also experienced profound transformation during this era, with Christianity taking root in a land once dominated by Celtic paganism. This process unfolded in stages, driven by the efforts of missionaries and local leaders.

Saint Patrick, a fifth-century missionary to Ireland, played a foundational role in the conversion of the Irish. Once a slave in Ireland, Patrick returned as a bishop, preaching the gospel and establishing churches throughout the island. His efforts led to the widespread acceptance of Christianity in Ireland, which in turn became a center of monastic learning and missionary activity.

Columba, a sixth-century Irish monk, carried the gospel to Scotland, founding the influential monastery at Iona. From this base, the Christian faith spread among the Picts and other tribes of northern Britain.

In England, Pope Gregory the Great sent Augustine of Canterbury to evangelize the Anglo-Saxons in 597 AD. Augustine established his mission in Kent, converting King Æthelberht and laying the foundation for the Christianization of England. Over time, the efforts of Augustine and his successors brought the various kingdoms of England under the influence of the Roman Church.

The Conversion of Germany and the Netherlands

The evangelization of Germany and the Netherlands was a slow and challenging process, marked by the dedication of missionaries like Boniface and Willibrord.

Willibrord, often called the “Apostle to the Frisians,” worked in the late seventh and early eighth centuries to spread the gospel among the peoples of the Netherlands. His efforts were supported by the Frankish monarchy, which sought to extend both political and religious influence into the region.

Boniface, an English missionary, became one of the most prominent figures in the Christianization of Germany. In the eighth century, Boniface demonstrated unparalleled courage and faith as he directly confronted pagan practices. The most dramatic example came when he felled the sacred oak of Thor at Geismar, a tree venerated by the local people as a symbol of the power of their gods.

With the gathered tribes watching in stunned silence, Boniface approached the mighty oak armed with nothing but an axe and the gospel of Christ. Tradition holds that as Boniface struck the tree, a great wind arose and toppled the oak, splitting it into pieces. The crowd, anticipating Thor’s wrath, instead witnessed the complete impotence of their god.

Seizing the moment, Boniface proclaimed the supremacy of Christ, the true God who created heaven and earth. The people, overwhelmed by the power of this demonstration and Boniface’s boldness, renounced their pagan practices and accepted baptism. The wood from the shattered oak was used to construct a chapel, symbolizing the triumph of the gospel over the old gods. Boniface’s actions not only converted many but also cemented his legacy as a fearless champion of Christ.

The Importance of Pope Gregory the Great

Pope Gregory I, known as Gregory the Great, was one of the most influential figures in this period of transformation. Serving as pope from 590 to 604 AD, Gregory combined spiritual leadership with practical governance, steering the church and its people through a time of crisis.

Gregory’s contributions included organizing relief efforts during famine and plague, reforming the liturgy, and emphasizing pastoral care. His writings, particularly The Pastoral Rule, became a standard for clergy throughout the Middle Ages.

Gregory also played a key role in missionary work, most notably in sending Augustine to England. His vision of the church as a unifying and civilizing force shaped the development of Western Christendom, and his leadership marked a turning point in the transition from the classical world to the medieval age.

Moving into the Middle Ages

By the eighth century, Europe had begun to stabilize under the leadership of Christian rulers and the guidance of the church. The chaos of the post-Roman period gave way to a new order, characterized by the fusion of Roman, Germanic, and Christian elements. The church’s influence extended into every aspect of life, from governance and education to art and culture.

This period marked the beginning of the Middle Ages, an era defined by the dominance of the church and the gradual emergence of medieval kingdoms. While far from perfect, this new society preserved the spiritual and cultural legacy of the ancient world, ensuring its transmission to future generations.

Conclusion

From an evangelical Protestant perspective, the transformation of Europe after the fall of Rome is a testimony to God’s providence and the resilience of the gospel. Despite the upheaval of invasions and the challenges of cultural integration, the church remained steadfast in its mission to proclaim Christ.

We celebrate the courage and faithfulness of those who carried the gospel to new lands, often at great personal cost. Yet, we also recognize the dangers that arose during this period, including the growing institutionalization of the church and the blending of political power with spiritual authority.

As we reflect on this history, we are reminded of the transformative power of the gospel, which transcends cultural and political boundaries. The story of Europe’s conversion is not just a tale of kings and missionaries—it is a testament to the enduring truth of Christ’s words: “I will build my church, and the gates of hell shall not prevail against it” (Matthew 16:18).

May we, like the missionaries and leaders of this era, remain committed to the unchanging gospel, bringing its hope to a world in need of transformation.

Resources

Bruce L. Shelley, Church History in Plain Language (Nashville: Thomas Nelson, 1995).

Justo L. González, The Story of Christianity, Vol. 1: The Early Church to the Dawn of the Reformation (New York: HarperCollins, 1984).

B.K. Kuiper, The Church in History (Grand Rapids:L Wm. B. Eerdmans Publishing Company, 2001).

Unless otherwise indicated, all Scripture quotations are from The ESV® Bible (The Holy Bible, English Standard Version®), © 2001 by Crossway, a publishing ministry of Good News Publishers. Used by permission. All rights reserved.