Five Good Emperors

In Ancient Roman history, the period between 96 and 180 is known as the age of the Five Good Emperors. The rulers commonly known were Nerva, Trajan, Hadrian, Antoninus Pius, and Marcus Aurelius. 
Term.
The term was first used by Niccolò Machiavelli in his book "The Discourses on Livy" from 1531: