Around the year 965, King Harald Bluetooth of Denmark and his Viking warriors were discussing which god was most powerful. Some favored mighty Thor, who defeated giant trolls with ease and caused lightning by throwing his hammer. Others picked Odin the Wise on his eight-legged horse, leading a horde of all dead warriors who ever perished in battle. One mentioned mischievous Loki, who tricked the other gods to serve his evil purposes.

But what about this new god, Hvíta Kristr, White Christ, who was said to rule the hosts of heaven?

A foreign priest named Poppo at this meeting was a servant of Hvíta Kristr. The Viking warriors called upon him to prove the power of his god.

At the forge of the smith, so the story goes, Poppo took a red-hot iron and held it in his hand. When he set it down, the king looked at his hands. There was not the slightest sign of injury.

That was enough for King Harald Bluetooth. He was baptized without delay and ordered all his subjects to follow his example.

Even if it did take a miracle to formally convert King Harald's realm to Christianity, the process did not begin that instant. For two centuries a variety of forces had been at work to bring the Christian faith to Denmark, but none so important as the missionary presence.

The first missionary to Denmark was Willibrord, an Irish monk known more for his work in Friesland than in Scandinavia. In his efforts to evangelize Friesland (now parts of the Netherlands and Germany), he visited Denmark briefly in the early 700s, returning with 30 Danish boys to educate as Christians.

But as often happened in Denmark's turbulent history, missionary work was interrupted by war. In 772 the great Frankish emperor Charlemagne launched a crusade into Saxony, and his troops slowly conquered and forced its conversion to Christianity. In less than 30 years, his armies approached the borders of Denmark, which was ruled by a powerful king named Godfred.

To Godfred and his Danes, it seemed obvious that Frankish conquest and Christianity went hand in hand. They did not want to be conquered, so that meant they had to reject Christianity, as well. He built a great wall, the Dannevirke, along his southern border and manned it with warriors to hold back the Franks. Then he launched a counter-attack, sending waves of Viking ships to harry the coasts of the Frankish empire, and the crusade was stopped cold.

But Christian merchants ventured where Frankish armies could not go. They traveled to Hedeby, just beyond the Dannevirke, where they traded with the pagan Danes, sustaining a Christian presence.

Vanguard churches

A quarter-century after the Danes repulsed Charlemagne's troops, they found themselves immersed in civil war. One of the contending princes, Harald Klak, sailed to the Frankish empire to seek the aid of Charlemagne's son, Emperor Louis the Pious. As part of the alliance, Harald and a great host of his Viking followers were baptized, and Ansgar became Harald's chaplain.

It was a position that Ansgar, a devout monk from Picardy, longed for, despite the dangers. "Since there could not be found a preacher who would go with them to the Danes because of their barbarous cruelty—on account of which everyone shuns that people," Adam of Bremen writes in his History of the Archbishops of Hamburg-Bremen, "the blessed Ansgar, inspired … by the Holy Spirit and desirous of obtaining martyrdom … presented himself."

Unlike other hagiographies of saints' lives, Ansgar's is not replete with miracles and signs. While Rimbert, his biographer and successor, writes that many were healed during his ministry, Ansgar himself denied he had any such gift. "Were I worthy of such a favor from my God," he told one of his followers, "I would ask that he would grant to me this one miracle, that by his grace he would make of me a good man."

Ansgar's patron, Harald Klak, never actually returned to Denmark (now ruled in part by Swedish overlords), but the evangelist got his wish to visit there briefly in 829.

Three years later, the pope, hearing of Ansgar's missionary passion, appointed him archbishop of Hamburg with the mission of converting Scandinavia to Christianity. It took another dozen years, however, before Ansgar won the right to establish a church in Hedeby, after which more Christian merchants moved to the town and a few Danes became Christians. Soon, a second Danish church was established in the North Sea port of Ribe.

"By God's favor the church of Christ was established both among the Danes and among the Swedes, and priests are functioning unhindered in their proper office," Ansgar happily announced.

As a child, Ansgar had reportedly received visions as a child of God telling him, "Go and return to me crowned with martyrdom." But in 865 he lay on his deathbed not because of persecution but illness, and "became very sad," lamented his biographer, and Ansgar kept repeating, "Thou are just, O Lord, and thy judgment is righteous." Just before his death, however, he experienced another vision that assured him he had been faithful.

For all Angsar's devotion and effort, Denmark remained pagan for another century save the tiny churches in Hedeby and Ribe. As Adam of Bremen wrote, "Let it suffice us to know that up to this time all the kings of the Danes had been pagans, and amid so great changes of kingdoms or inroads of barbarians, some small part of the Christianity that had been planted by Ansgar had remained, the whole had not failed."

Preaching to the king

During these next decades, Danish Vikings increasingly encountered Christians on their raids abroad. Back home, they began to weave stories of Hvíta Kristr into tales of Odin and Thor, Frey and Freya, Balder and Loki, Ull the winter god, giants, trolls, water sprites, mermaids, sea serpents, and all the other supernatural beings of the Nordic pantheon.

In 934 international politics again entered the picture. Christian troops from the Holy Roman Empire forced the Swedish ruler to submit and accept baptism, which meant, again, that Denmark was officially Christian. But then came another pagan reaction against Christianity, Danish independence, and the beginning of the rule of the heathen King Gorm.

Though Archbishop Unni of Hamburg preached in his court, Gorm remained hostile to Christianity. His son, Harald Bluetooth (who co-ruled with his father), listened sympathetically. Harald even allowed missionaries to baptize Danes.

After Gorm died, Harald extended his authority in many directions. When he converted (after his encounter with Poppo), he was at the height of his power, and there was little resistance when he commanded all his subjects to become Christians.

Yet politics entered into even this decision. By 965, King Harald knew he was powerful enough to accept the Christian religion without succumbing to German political domination. He knew that his new faith, in fact, would help him to solidify his own control over his extensive realm. But whatever his motives, King Harald became an exemplary Christian, and the new religion began to penetrate more deeply into the country.

Eventually, his son, Svend Forkbeard, rose in revolt, and Harald was forced to flee. But Svend was a Christian like his father and, with royal patronage, Christianity continued to grow in Denmark. When Svend died suddenly in 1014, his Christian son, Knut ("the great," the king who killed Norwegian Olaf Haraldsson, the saint, in battle) succeeded him as ruler of a Danish empire that now included England and Norway.

Two centuries had passed since the mission voyages of Ansgar, and 70 years since the miracle of Poppo. Denmark had become a solidly Christian country, and bells were ringing every Sunday from some 500 churches throughout the land. Pagan superstitions still lingered, but Hvíta Kristr was triumphant at last among the Danes.

J. R. Christianson is research professor of history at Luther College in Decorah, Iowa, and editor of Scandinavians in America (Symra, 1985).