Written on mobile so please excuse any errors or typos.

I will rely mostly on Dio Cassius as he is the most reputable primary source on the Nerva-Antonines.

The Nerva-Antonine emperors were seen as good for the empire save for Commodus, whose accession to the throne was lambasted by Dio Cassius.

Nerva reigned only fifteen months however he had the unenviable task of following the totalitarian reign of Domition. Nerva, while being elderly and in poor health needed to walk the fine line between the senate and praetorian guard, the latter of which was opposed to his reign. Dio lists the actions of Nerva and does not dispute his claim of ruling extraordinarily well.

'Nerva ruled so well that he once remarked: "I have done nothing that would prevent my laying down the imperial office and returning to private life in safety."'

Nerva did quite well in erasing the evidence of Domitian's rule however he remained unpopular with the Praetorian guard and eventually selected Trajan, a popular general, to follow him. This selection mollified this opponents as Trajan could command and control the armies and Praetorian Guard.

Trajan is often seen as the stereotypical, and in a way, archetypical Roman Emperor, despite the rumors of his wife's immense power over him. Trajan ruled fairly as seen with his letter to Pliny the Younger, the governor of Pontus regarding fair treatment of Christians in the empire. He won numerous military victories, defeating the Dacians and Parthians. He did not embroil himself in the rumors of plots and denigration of advisors and court members.

"For by nature he was not at all inclined to duplicity or guile or harshness, but he loved, greeted and honoured the good, and the others he ignored; moreover, he had become milder as the result of age."

"Then on the following day he said to his friends who were constantly in the habit of making disparaging remarks about Sura: "If Sura had desired to kill me, he would have killed me yesterday." Now he did a fine thing in running the risk in the case of a man who had been calumniated, but a much finer thing still in believing that he never should be harmed by him. Thus it was that the confidence of his conviction was strengthened by his personal knowledge of Sura's conduct rather than by the conjectures of others."

"Indeed, the emperor himself barely missed being wounded as he was riding past, in spite of the fact that he had laid aside his imperial attire to avoid being recognized; but the enemy, seeing his majestic gray head and his august countenance, suspected his identity, shot at him and killed a cavalryman in his escort."

Dio portrays Trajan as a fair and wise leader who ruled well and maintained his authority through fair treatment and military victory.

Hadrian receives praise from Dio in his fair rulings and judgement despite the dislike brought on by the executions he ordered later in his career. Overall Dio characterizes Hadrians reign as "excellent" and provides a characterization of Hadrian to mitigate the executions ordered.

"Yet he was so far from being of a bloodthirsty disposition that even in the case of some who clashed with him he thought it sufficient to write to their native places the bare statement that they did not please him. And if it was absolutely necessary to punish any man who had children, yet in proportion to the number of children he would lighten the penalty imposed."

"Hadrian was hated by the people, in spite of his generally excellent reign, on account of the murders committed by him at the beginning and end of his reign, since they had been unjustly and impiously brought about."

"Nevertheless, the senate persisted for a long time in its refusal to vote him the usual honours and in its stricture upon some of those who had committed excesses during his reign and had been honoured therefor, when they ought to have been punished."

Here Hadrian remarks the senate withheld honors because of the executions order before his death. Those executed were of the senatorial class and as such, the people who Dio states hated Hadrian is more than likely the senate who hated him.

Antoninus Pius is not mentioned in the books of Dio Cassius more likely than not due to the book concerning him was destroyed through time. The only source on his life comes from the Historiae Augustae, a text of volatile provenance and dubious historical accuracy at best. Overall he was considered a just and good emperor and maintained the empire well.

"His proconsulship in Asia he conducted in such a fashion that he alone excelled his grandfather..."

"His father, as long as he lived, he obeyed most scrupulously..."

"He was deified by the senate, while all men vied with one another to give him honour, and all extolled his devoutness, his mercy, his intelligence, and his righteousness. All honours were decreed for him which were ever before bestowed on the very best of emperors. He well deserved the flamen and games and templeand the Antonine priesthood. Almost alone of all emperors he lived entirely unstained by the blood of either citizen or foe so far as was in his power, and he was justly compared to Numa, whose good fortune and piety and tranquillity and religious rites he ever maintained."

These excerpts from the Historiae Augustae Effectively paint Augustus as the model of Roman manhood and imperial stature. It continues to extol his virtues and his ability to lead.

Marcus Aurelius was held in high regard by Dio and he extolled the virtues he displayed. Some of them may be exaggerated such as burning Faustinas' papers however Dio discusses how Marcus Aurelius maintained himself as honorable, "humble," and fair. Dio also consistently praises Marcus Aurelius for his education and continued dedication to philosophy and learning.

"Indeed, while still a boy he so pleased all his relatives, who were numerous, influential and wealthy, that he was loved by them all; and when Hadrian, chiefly for this reason, had adopted him, he did not become haughty, but, though young and a Caesar, served Antoninus most loyally throughout all the latter's reign and without giving offence showed honour to the others who were foremost in the State."

"And yet Marcus destroyed all the papers that were found in the chests without reading any of them, in order that he might not learn even the name of any of the conspirators who had written anything against him and so be reluctantly forced to hate them."

"However, he did not meet with the good fortune that he deserved, for he was not strong in body and was involved in a multitude of troubles throughout practically his entire reign. But for my part, I admire him all the more for this very reason, that amid unusual and extraordinary difficulties he both survived himself and preserved the empire."

"He was always steeping himself in Greek and Latin rhetorical and philosophical learning, even after he had reached man's estate and had hopes of becoming emperor."

Marcus was seen as a good emperor however his decision to promote Commodus as his successor was highly criticized.

Commodus was the last of the Nerva-Antonine dynasty with disastrous results. Commodus was notorious for his appearances in the Games, particularly the hunt, or venationes, an act seen as disgraceful to the elite of Roman society as actors and gladiators were seen as amoung he lowest in Roman society. To have the emperor right and hunt in the area was seen as disgraceful to the throne and to the senatorial class.

"That spectacle, of the general character I have described, lasted fourteen days. When the emperor was fighting, we senators together with the knights always attended. Only Claudius Pompeianus the elder never appeared, but sent his sons, while remaining away himself; for he preferred even to be killed for this rather than to behold the emperor, the son of Marcus, conducting himself in such a fashion."

"And this story was believed, too, because he had once got together all the men in the city who had lost their feet as the result of disease or some accident, and then, after fastening about their knees some likenesses of serpents' bodies, and giving them sponges to throw instead of stones, had killed them with blows of a club, pretending that they were giants."

"This fear was shared by all, by us senators as well as by the rest. And here is another thing that he did to us senators which gave us every reason to look for our death. Having killed an ostrich and cut off his head, he came up to where we were sitting, holding the head in his left hand and in his right hand raising aloft his bloody sword; and though he spoke not a word, yet he wagged his head with a grin, indicating that he would treat us in the same way."

Dio makes many statement as to the delravity of Commodus and even in his death he talks of his excesses in food and wine causing him to vomit up the poison intended to kill him. Commodus was unliked by the elites of Roman society and as a result of his transgressions, he was assassinated by those around him.

Overall the Nerva-Antonine dynasty was seen as a group of exemplary emperors who were just and fair. However it is important to be cautious of ancient sources such as Dio as he was writing under the rule of Septimius Severus, an emperor who styled himself after the Antonines and Marcus Aurelius. Especially because many sources were written decades or even centuries after the events occurred, the historians were subject got the biases of the senate and particularly of the current emperor.

Sources:

Dio Cassius: Roman History

Historiae Augustae