Early modern period
In the early modern period, the Holy Roman Empire was a union of territories in Central Europe under a Holy Roman Emperor the first of which was Otto I. The last was Francis II, who abdicated and dissolved the Empire in 1806 during the Napoleonic Wars. Despite its name, for much of its history the Empire did not include Rome within its borders.
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.