After the period of the 12 Caesars
came a time when Rome was ruled by five good emperors in a row. At the start of the first chapter of his Decline and Fall of the Roman Empire
, historian Edward Edward Gibbon
"During a happy period of more than fourscore years, the public administration was conducted by the virtue and abilities of Nerva, Trajan, Hadrian, and the two Antonines."
Each emperor adopted his successor. The final emperor was Marcus Aurelius whose natural son followed him and broke the string of Roman luck.
Nerva (r. A.D. 96-98)
Marcus Cocceius Nerva was the first of the five good emperors (those sandwiched between bad emperors Domitian and Commodus). Nerva was a 60-year-old senator whose support came from the Senate. To gain Praetorian favor, Nerva appointed Trajan his successor.
Trajan (r. A.D. 98-117)
Trajan was born at Italica, in Spain, on September 18, A.D. 53. He spent most of his life on campaigns and was named optimus
'best' by the Senate. After having appointed Hadrian his successor, Trajan died while returning to Italy from the east, on 9 August A.D. 117.
Hadrian (r. A.D. 117-138)
Hadrian was the second century Roman emperor who is known for his many building projects, cities named Hadrianopolis (Adrianopolis) after him, and the famous wall across Britain designed to keep the barbarians out of Roman Britain
. Despite all he did, were it not for his successor's efforts, Hadrian would not have made it to this list.
Antoninus Pius (r. A.D. 138-161)
When Hadrian's adopted son Verus died, he adopted Antoninus Pius as son and successor. As part of the deal, Antoninus Pius adopted the future Emperor Marcus Aurelius. When Hadrian died, Antoninus demonstrated such piety towards his adopted father that he earned the name "pius." He completed and restored earlier building projects rather than starting major ones of his own.
Marcus Aurelius (r. A.D. 161-180)
The second of Gibbon's Antonine pair was Marcus Aurelius Antoninus, Stoic philosopher and Roman emperor. His philosophical writings are known as the Meditations
. He is considered the last of the five good emperors and was succeeded by his son, the infamous Roman emperor Commodus.