285 diocletian appoints maximian as caesar and co ruler
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285 1741 years ago Historical Events July 21 3 sources

Diocletian appoints Maximian as Caesar and co-ruler.

On July 21, in the year 285, Diocletian appoints Maximian as Caesar and co-ruler. This event is recorded as a Historical Events event in the history of July 21, one of 430 recorded events on this date across all of history.

Diocletian, nicknamed Jovius, was Roman emperor from 284 until his abdication in 305. He was born Diocles to a family of low status in the Roman province of Dalmatia. As with other Illyrian soldiers of the period, Diocles rose through the ranks of the military early in his career, serving under Aurelian and Probus, and eventually becoming a cavalry commander for the army of Emperor Carus. After the deaths of Carus and his son Numerian on a campaign in Persia, Diocles was proclaimed emperor by the troops, taking the name "Diocletianus". The title was also claimed by Carus's surviving son, Carinus, but Diocletian defeated him in the Battle of the Margus.

Key Facts

  • This event took place on July 21, 285 (AD era).
  • It is categorised as a Historical Events event in recorded history.
  • Referenced in 3 Wikipedia articles.
  • Wikipedia source last updated on 16 July 2026.

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This article draws on content from Wikipedia, available under CC BY-SA 4.0.

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