November 284 · Nicomedia (Asia Minor) Theater
November 284
After the death of Numerian, the army proclaimed the Illyrian officer Diocletian emperor near Nicomedia on 20 November 284. Carinus still ruled in the West; their armies did not meet until the Battle of the Margus in 285. Diocletian subsequently reconstructed imperial government, taxation, coinage, and military organization and later shared authority through the Tetrarchy.
Commanders