Christianity became the official state religion of the Roman Empire under Emperor Constantine.
It united Romans but the Western Roman Empire fell in 476 CE.
The Eastern Roman Empire, or Byzantine Empire, maintained Eastern Orthodox Christianity, which rulers used to consolidate their centralized power.
By 1200, the Byzantine Empire had lost territory to Islamic powers but still had influence until 1453 when the Ottoman Empire sacked Constantinople, renaming it Istanbul, ending the Byzantine Empire.
Eastern Orthodox Christianity was then embraced by the Kievan Rus, who adopted Byzantine architectural styles, the alphabet, and church-state organization.
In Western Europe, Roman Catholicism provided a common structure with the church hierarchy (popes, bishops, cardinals) despite political fragmentation.
The Church initiated the Crusades, religious wars against Muslims, which connected Europeans to larger trade networks.
Islam and Judaism existed as minority religions.
Muslims controlled the Iberian Peninsula after an invasion in the 8th century.
Jews, scattered throughout Europe, facilitated trade but faced anti-Semitism.
Political Organization
Around 1200, Europe lacked large empires, unlike the Americas (Aztecs, Incas), China (Song Dynasty), and Islamic empires.
Western Europe was characterized by decentralization and political fragmentation, organized around feudalism.
Feudalism
A system of allegiances between powerful lords and monarchs.
Greater lords and kings gained allegiance from lesser lords and kings, with land exchanged for loyalty.
Manorialism
Patches of land were independently owned and ruled, organizing peasants into serfs.
Serfs were bound to the land and worked in exchange for protection from the lord and his military forces.
Serfs were not owned but were bound to the land.
Around 1200, monarchs began to centralize power by creating large militaries and bureaucracies, challenging the power of the European nobility.
Increased centralization led to competition and wars of conquest among monarchs vying for influence and territory.