But empires move, though rulers bid them stand still.
His other writings include: Church Courts and Church Discipline (1843); Doctrine of the Holy Eucharist (1853); Doctrine of the Incarnation in Relation to Mankind and the Church (1848 and later editions); The Five Empires, a Sketch of Ancient History (1840); A Sketch of the History of Erastianismn (1851); An Enquiry into the Principles of Church Authority (1854); and a romance, Rutilius and Lucius (1842).
In 803 and 810 he made a treaty with Charlemagne, by which the limits of the two empires were amicably fixed.
But he had little success, and soon concluded a treaty by which both empires promised toleration to the worshippers of the two rival religions, Christianity and Zoroastrianism.
The two great empires, Assyria and Babylon, which grew up on the banks of the Tigris and Euphrates, can be separated as little historically as geographically.