Question

how many roman emperors ruled during the 50-year period

Answer 1

Nineteen emperors ruled Rome from 235 C.E to 285 C.E
The chart below I hope explains it.
Hope this helps! ^_^ 

Answer 2

Answer: 19.

Explanation:

Beginning with the rule of Maximinus the Thracian, Rome began a five decades period of crisis and fell to decay throughout a long list of Emperors. The years from 235 to 285 CE were marked by a string of brief reigns, usually closing with the violent demise of the emperor. Thirteen of them are believed to have been assassinated.