 The surviving histories speak equally positively of Nerva 's brief reign , although none offer a substantial commentary on his policies . Both Cassius Dio and Aurelius Victor emphasize his wisdom and moderation , with Dio commending his decision to adopt Trajan as his heir . These views were later popularized by the 18th @-@ century historian Edward Gibbon in his History of the Decline and Fall of the Roman Empire . Gibbon considered Nerva the first of the Five Good Emperors , five successive rulers under whom the Roman Empire " was governed by absolute power , under the guidance of wisdom and virtue " from 96 until 180 . Nevertheless , even Gibbon notes that , compared to his successors , Nerva may have lacked the necessary qualifications for a successful reign : 
 The surviving histories speak equally positively of Nerva <a href='null_genetive' title='1'><mark>'s</mark></a>brief reign , although none offer a substantial commentary on his policies . Both Cassius Dio and Aurelius Victor emphasize his wisdom and moderation , with Dio commending his decision to adopt Trajan as his heir . These views <a href='uninflect' title='2'><mark>were</mark></a> later popularized by the 18th @-@ century historian Edward Gibbon in his History of the Decline and Fall of the Roman Empire . Gibbon considered Nerva the first of the Five Good Emperors , five successive rulers under whom the Roman Empire " was governed by absolute power , under the guidance of wisdom and virtue " from 96 until 180 . Nevertheless , even Gibbon <a href='uninflect' title='3'><mark>notes</mark></a> that , compared to his successors , Nerva may <a href='been_done' title='4'><mark>have</mark></a> lacked the necessary qualifications for a successful reign : 
The surviving histories speak equally positively of Nerva  brief reign , although none offer a substantial commentary on his policies . Both Cassius Dio and Aurelius Victor emphasize his wisdom and moderation , with Dio commending his decision to adopt Trajan as his heir . dese views was later popularized by da 18th @-@ century historian Edward Gibbon in his History of the Decline and Fall of the Roman Empire . Gibbon considered Nerva tdafirst of the Five gud Emperors , five successive rulers under whom the Roman Empire " was governed by absolute power , under the guidance of wisdom and virtue " from 96 until 180 . Nevertheless , even Gibbon note dat , compared to his successors , Nerva may done lacked the necessary qualifications fa a successful reign :