Although the reforms of Diocletian and Constantine produced a solid administration of empire and the army, the reforms also brought along a heavy tax burden. The most prosperous parts of the empire were in the rural villas, and not in the towns, as was the case previously. Wealthy landowners moved to their country homes and abandoned their city estates.
Much of the government revenue was spent on the Rhine-Danube frontier threat in the eastern provinces; the money was used to for army pay, weapons and clothing.
Between 356 AD and 360 AD, Julian fought against Franks and Alamanni in eastern Gaul; in the process, he restored the Rhine frontier. Many of his gains were squandered when he withdrew troops for the Persian campaign of 363 AD, the place where he was killed.
One of Julian's most famous exploits occurred when he attempted to restore the pagan faith. He failed miserably and the Christian bishops continued to exercise their authority in the later decades of the 4th century AD.