He obtained high military command under Probus and Aurelian and fought under Carus in Persia.  Declared emperor by his troops, this Dalmatian became sole ruler when [*] Carinus was murdered by his officers. To repel the Germans, he named Maximian augustus, and Constantinius I and Galerius caesars. For 10 points—name this man who succeeded Numerian, and served as emperor from 284 to 305.
He obtained high military command under Probus and Aurelian and fought under Carus in Persia.  Declared emperor by his troops, this Dalmatian became sole ruler when [*] Carinus was murdered by his officers. To repel the Germans, he named Maximian augustus, and Constantinius I and Galerius caesars. For 10 points—name this man who succeeded Numerian, and served as emperor from 284 to 305.
He obtained high military command under Probus and Aurelian and fought under Carus in Persia.  
Diocletian or Caius Aurelius Valerius Diocletianus