Diocletian was born in 244 AD to a family that was very poor. Since he was from a low station in life you would think he would never become emperor but he did how? He joined the military and rose in its ranks, and when the current emperor died, Diocletian was declared the new emperor (he was part of the emperor body guard). When Diocletian became emperor in 284 AD the empire had been in a state of unrest for more than 50 years with 27 emperors ruling in that time. Diocletian decided that the empire was too big for one man to rule. So he split it in two and while he ruled in the east while a Roman general named Maximian ruled in the west and while this worked amazingly well while these two men were ruling since they didn’t try to get more power, it soon fell apart when power hungry emperors tried to take each others power.
Diocletian tried to bring the empire back to stability but it was still a challenge for example the Edict of Prices didn’t work (the Edict of Prices was made to stop enflation), many reforms didn’t work and the empire remained at war with its self throughout his reign. This was also the last time Christians were persecuted openly in the Roman empire.
In 305 AD Diocletian left his throne after getting sick while on one of his campaigns. He lived long enough to see the empire he created with two men ruling fail. He died on the 3 of December in 311 AD.