The prosperity of the Roman Empire reached its greatest height in the A.D. 100's.

The 'five good emperors' - Nerva, Trajan, Hadrian, Antonius Pius, and Marcus Aurelius - reigned in turn from A.D. 96 to 180. Their learning and devotion to duty made them loved as well as respected.

They are also called the Adopted Emperors because the dynastic principle was changed to adoptive emperorship (choice of the most fit to rule).