As we all know, Theodosius I was the last unified emperor of both the Eastern and Western halves of the Roman Empire. Clearing up the mess left by Valans at Adrianople, he battled Goths, usurpers and heretics to Nicene orthodoxy in a time of tumult for the Empire.
It was also an interesting time in the history of the early church. During Theodosius' reign, Bishop Ambrose of Milan formulated the doctrine that whilst the Emperor ruled matters temporal, the Church was in charge of matters spiritual. This was an important development in the history of Western thought. One of the Emperors' many titles was Pontiff Maximus - the highest religious office in the Roman World. By the act of giving away this authority, the later emperors allowed the church to control both religious life on earth and - more importantly - the path to salvation in the afterlife. This segregation of church and state persisted until at least the Renaissance and, arguably, through to the Bishop of Rome even now.
Ambrose was a combative sort who liked to defend the church's rights. He excommunicated Theodosius following a massacre of civilians in Thessalonica in 390. More interesting to the modern world, perhaps, was his meddling in imperial matters. A christian mob burnt down a synagogue in Callinicum, Mesopotamia and Theodosius ordered the local bishop to rebuild the temple. Ambrose argued that Theodosius should retract this as he was ordering the local bishop to act against either truth or death.
Theodosius backed down and the synagogue in Callinicum was not rebuilt.
Today Callincum goes by its Syrian name of Raqqa.
History is somewhat wider than living memories.