>>132419I guess he just doesn't want another Commodus. Every time a great Emperor dies, the empire goes to shit by their heirs.
Also he did way more than just raping Bulgaria into submission. He enriched the empire, defeated many foreign enemies (e.g. Armenians, Georgians, Arabs, Germans and Lombards.) and grew the army up to around 100k soldiers (for comparison, Trajan had 150k Legionaries across the entire Empire), defeated usurpers, and stamped down on corruption.