How did Charlemagne expand Frankish power and spread Christianity?

Charlemagne expanded Frankish power and spread Christianity through a combination of relentless military campaigns, strategic diplomacy, and administrative reform.

Military Expansion

Charlemagne’s reign was defined by decades of warfare aimed at securing his borders and expanding his realm. His most significant and brutal conflict was the 30-year conquest of the Saxons, which involved mass killings, deportations, and forced conversions to break their resistance. He also annexed Bavaria and destroyed the Avar empire, opening new territories to missionary work. In the south, he intervened in Italy to defeat the Lombards, assuming their crown and reaffirming his role as protector of the papacy.123

Religious Policy

Charlemagne viewed the propagation of Christianity as a core responsibility of his governance. He integrated religious reform into public policy, using royal capitularies to standardize liturgical practices, improve the quality of the clergy, and root out paganism. While his early efforts in Saxony were marked by draconian measures—such as the death penalty for refusing baptism—his approach later evolved toward less brutal methods of conversion. By positioning himself as the "rector of the new Israel," he successfully aligned his political expansion with the interests of the church, securing ecclesiastical support for his rule.42