Recognizing that the empire’s wealth and threats were now in the East, he moved the capital to Byzantium, renaming it "New Rome" (Constantinople). Conclusion

Germanic tribes crossed the Rhine and Danube, while the Sassanid Persians pressured the East.

Severus shifted the empire’s power base away from the Senate and toward the military. While this provided short-term stability, it created a dangerous precedent. His successors, including the notorious , expanded citizenship to nearly all free inhabitants of the empire (the Constitutio Antoniniana ), primarily to increase tax revenue for a ballooning military budget. However, the dynasty ended in chaos with the assassination of Alexander Severus in 235 AD, triggering a half-century of near-total collapse. The Crisis of the Third Century (235–284 AD)

The empire physically broke apart into three pieces: the Gallic Empire in the west, the Palmyrene Empire in the east, and the Roman core. Diocletian and the Tetrarchy (284–305 AD)

He took an active role in church doctrine, seeking to unify the faith.