Holy Roman Empire
The empire was dissolved on 6 August 1806, when the last Holy Roman Emperor Francis II (from 1804, Emperor Francis I of Austria) abdicated, following a military defeat by the French under Napoleon at Austerlitz (see Treaty of Pressburg). Napoleon reorganized much of the Empire into the Confederation of the Rhine, a French satellite. Francis' House of Habsburg-Lorraine survived the demise of the empire, continuing to reign as Emperors of Austria and Kings of Hungary until the Habsburg empire's final dissolution in 1918 in the aftermath of World War I.
East–West Schism
Disunion in the Roman Empire contributed to disunion in the Church. Theodosius the Great, who in 380 established Nicene Christianity as the official religion of the Roman Empire (see Edict of Thessalonica), was the last Emperor to rule over a united Roman Empire. Following the death of Theodosius in 395, the Empire was divided for the final time into western and eastern halves. In the 4th century, the Roman emperor (reigning in Constantinople) started to control the Church in his territory.