How a series of medieval wars accidentally birthed the Papal States and Western Europe
Between 568 and 750, the Byzantine Empire lost its grip on Italy to the invading Lombards. This slow collapse forced the Papacy to evolve from a religious institution into a political power, ultimately realigning the Church away from Byzantium and toward the Frankish Kingdom, changing European history forever.
The conflict began on Easter Monday, 568, when the Lombard king Alboin led his people into Northern Italy. The Byzantine Empire, distracted by military pressures on its Arab and Slavic frontiers, failed to provide adequate defense. As imperial forces retreated, the burden of governance and protection fell upon local Italian aristocrats and the Papacy. By the time the Lombards conquered the Exarchate of Ravenna in 750, the Byzantine presence in Italy had become a hollow shell.
As the Empire struggled, its relationship with the Papacy fractured. Byzantine emperors, preoccupied with theological disputes like Iconoclasm and Monophysitism, alienated their Italian subjects. When Emperor Leo III attempted to increase taxes on Papal estates in 722/723, the Pope refused to pay. This tension turned the Papacy into an independent political actor. Pope Gregory II began organizing his own defenses, and later, Popes even struck alliances with Lombard dukes to protect their interests, effectively defining their territory as a distinct 'holy republic' separate from imperial control.
The final rupture occurred when the fall of Ravenna left the Pope vulnerable. Emperor Constantine V, focused on other reconquests, offered only diplomatic envoys rather than military aid. Realizing that Byzantium could no longer protect them, the Papacy turned to the Frankish Kingdom for security. This strategic shift not only solidified the Papacy's territorial claims but also laid the foundational geopolitical structure for the future Holy Roman Empire, marking the definitive end of Byzantine influence in the region.
Source: Byzantine–Lombard wars
