What happened 285 AD

Carinus left Rome at once and set out for the east to meet Diocletian. On his way through Pannonia, he put down the usurper Sabinus Julianus and in July 285 he encountered the army of Diocletian at the Battle of the Margus River (the modern Morava River) in Moesia.

Historians differ on what then ensued. At the Battle of the Margus, according to one account, the valor of his troops had gained the day, but Carinus was assassinated by a tribune whose wife he had seduced. Another account represents the battle as resulting in a complete victory for Diocletian and claims that Carinus' army deserted him. This account may be confirmed by the fact that Diocletian kept in service Carinus' Praetorian Guard commander, Titus Claudius Aurelius Aristobulus.

Diocletian may have become involved in battles against the Quadi and Marcomanni immediately after the Battle of the Margus. He eventually made his way to northern Italy and made an imperial government, but it is not known whether he visited the city of Rome at this time.

Conflict boiled in every province, from Gaul to Syria, Egypt to the lower Danube. It was too much for one person to control, and Diocletian needed a lieutenant. At some time in 285 at Mediolanum (Milan), Diocletian raised his fellow-officer Maximian to the office of caesar, making him co-emperor.

Nevertheless, if Diocletian ever did enter Rome shortly after his accession, he did not stay long; he is attested back in the Balkans by 2 November 285, on a campaign against the Sarmatians.

Feeling the kingdom was now secure, Ptolemy shared rule with his son Ptolemy II by Queen Berenice in 285 BC.

The Library of Alexandria, in Egypt, was the largest and most significant great library of the ancient world. It flourished under the patronage of the Ptolemaic dynasty and functioned as a major center of scholarship from its construction in the 3rd century BC until the Roman conquest of Egypt in 30 BC.