In the year 710, a monk named Willibrord stood in Schleswig, then part of Denmark, and preached to King Ongendus. The king listened with respect but showed no interest in abandoning his old gods. Willibrord took thirty young men back to Frisia, perhaps hoping to educate them for future service. A century later, in 823, Archbishop Ebbo of Reims baptized a few people during a visit to Denmark. He returned twice more without recorded success. In 826, Harald Klak, King of Jutland, fled his homeland after being forced out by Horik I. He sought help from Emperor Louis I of Germany. Louis offered him the title of Duke of Frisia if he would abandon the old gods. Harald agreed, and four hundred Danes with him were baptized at Ingelheim am Rhein. Ansgar accompanied Harald back to Jutland to oversee Christianity among the converts. When Harald was driven out again, Ansgar turned his attention to Sweden. He traveled to Birka in 829 and established a small Christian community there. His most important convert was Herigar, a town prefect and counselor to the king. In 831, the Archdiocese of Hamburg was founded to take responsibility for proselytizing Scandinavia. Horik I sacked Hamburg in 845, forcing the seat of the archdiocese to move to Bremen. That same year, a pagan uprising in Birka resulted in the martyrdom of Nithard and forced Bishop Gautbert to flee. Ansgar returned to Birka in 854 and to Denmark in 860 to reestablish some gains. He won the trust of King Horik II, who gave him land in Hedeby for the first Christian chapel. A second church was founded later in Ribe on Denmark's west coast. Ribe became an important trading town, and southern Denmark was made a diocese in 948 under its first bishop, St. Leofdag, who was murdered that year while crossing the Ribe River.
Royal Conversion Strategies
Harald Bluetooth declared around AD 965 that he had made the Danes Christian and raised the larger of two Jelling Stones to commemorate it. The stone bears an inscription claiming this conversion. Harald Klak was the first Danish king to convert, baptizing himself during exile to receive support from Louis the Pious. However, historian Sanmark considers his impact minor since he likely never returned home. Christianity gained strong hold only after Harald Bluetooth converted around 960. Reports say Frisian monk Poppo held a fire-heated lump of iron without injury, convincing the king. Harald's daughter Gunhilde and son Sweyn Forkbeard were baptized too. German histories record Harald being baptized in the presence of Emperor Otto I, Sweyn Forkbeard's godfather. One consequence was that Danish kings abandoned the old royal enclosure at Jelling and moved their residence to Roskilde on Zealand. Sweyn rebelled against his father, spending vast time and money raising the great stone at Jelling. King Harald asked a traveler if they had seen human beings move such a heavy load. A traveler replied that Sweyn had dragged all of Denmark away from him. Several battles brought the rebellion to stalemate until 985 when Harald was wounded by an arrow and died in Jomsborg. In Norway, Olaf Tryggvason became King Olaf I in 995. He used every means available to convert the country. He raided European cities before meeting a Christian seer on the Isles of Scilly in 986. After recovering from wounds sustained during a mutiny, he let himself be baptized. He stopped raiding Christian cities and lived in England and Ireland. When he returned to Norway, Haakon Jarl faced a revolt. Olaf convinced rebels to accept him as king. Haakon Jarl was later betrayed and killed by his own slave while hiding in a pig sty. Olaf expanded efforts to Norse settlements in the west, crediting himself with Christianizing the Faroes, Orkney, Shetland, Iceland, and Greenland.