Papal Correspondence on March 13, 1138: An Appeal to King Lothair III

On March 13, 1138, Pope Innocent II issued a compelling letter to King Lothair III of Germany, advocating for the conversion of the pagan Slavs residing in the Baltic region. This letter serves as a significant testament to the Catholic Church’s concerted efforts during the 12th century to expand Christianity into Northern and Eastern Europe—a mission which formed part of a broader ecclesiastical strategy.

Historical Context

The 12th century marked a critical period in the religious and political landscape of Europe, characterized by efforts to establish and consolidate Christianity in regions still practicing indigenous pagan beliefs. The papacy often collaborated with secular leaders to propagate the faith, viewing this mission as both a spiritual and civilizing endeavor.

Pope Innocent II’s Papacy

Pope Innocent II, who reigned from 1130 until his death in 1143, was known for his diplomatic skills and efforts to bolster the church’s influence across Europe. His tenure was marked by both internal struggles, such as the papal schism with Antipope Anacletus II, and external challenges, including the strengthening of the church’s reach into pagan territories.

The Appeal to King Lothair III

King Lothair III (Lothair of Supplinburg), Holy Roman Emperor and King of Germany, was approached by Pope Innocent II in an appeal that underscored the significance of religious unity and the expansion of Christendom into Slavic lands. The letter urged the King to leverage his political and military influence to promote Christian conversion among the Slavs—a group largely residing in areas that would become parts of modern-day Poland, eastern Germany, and the Baltic States.

Broader Significance and Aftermath

This appeal was not an isolated incident but part of a larger effort known as the Northern Crusades—a series of campaigns aimed at converting the pagan populations of Northern Europe, including the Wends, a sub-group of the Slavs. The Northern Crusades were initiated mainly by German and Danish rulers, but papal endorsement lent significant credibility and impetus to these missions.

In the following decades, missions often backed by military crusades would lead to the eventual incorporation of these regions into the Christian world, although not without resistance and conflict.

Legacy

The letter from Pope Innocent II to King Lothair III highlights the intricate interplay between religious motives and political power during the medieval period. It also underscores the significant role played by the church in shaping medieval Europe’s spiritual and cultural geography. The conversion campaigns catalyzed by such papal initiatives laid the groundwork for the religious map of modern Europe and signaled the start of a new era of Christian dominance in formerly pagan territories.