History of the East–West Schism
Disunion in the Roman Empire further contributed to disunion in the Church. The Emperor Diocletian famously divided the administration of the eastern and western portions of the Empire in the early 4th century, though subsequent leaders (including Constantine) aspired to and sometimes gained control of both regions. Theodosius the Great, who 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 his death in 395, the division into western and eastern halves, each for a few decades still under its own Emperor, was never reunited.
Henry II, Holy Roman Emperor
Henry II (; ) (6 May 973 – 13 July 1024), also known as Saint Henry the Exuberant, Obl. S. B., was Holy Roman Emperor ("Romanorum Imperator") from 1014 until his death in 1024 and the last member of the Ottonian dynasty of Emperors as he had no children. The Duke of Bavaria from 995, Henry became King of Germany ("Rex Romanorum") following the sudden death of his second cousin, Emperor Otto III in 1002, was crowned King of Italy ("Rex Italiae") in 1004, and was crowned by the Pope as Emperor in 1014.