Two historical chaps seem to get a lot more praise than I think they deserve. To balance that, in a small measure, I wrote this about Marcus Aurelius and Henry II.
Marcus Aurelius was the last emperor of the Golden Age of Imperial Rome, and was succeeded by his son (possibly) Commodus. Both men will be relatively well-known as they feature in the entertaining film Gladiator. Marcus Aurelius also left a lasting impression on the Romans as a great emperor and a virtuous man.
However, he is dramatically overrated. Imperial Rome’s Golden Age happened because each emperor nominated an adopted, rather than actual, son to succeed him (or sons, Lucius Verus and Marcus Aurelius both succeeded Antoninus Pius). Marcus Aurelius chose otherwise, although there is doubt over whether Commodus was his son (possible this was fuelled by the latter’s horrendousness which made others want to disassociate the pair). Regardless, Marcus Aurelius, lauded as wise, left the empire in the hands of a murderous, bloodthirsty, incestuous mad bastard.
This did not have a positive impact on the Roman Empire.
Under the emperors from Nerva to Marcus Aurelius, men of high status and talent benefited. Emperors were unafraid of rivals and could promote the best men to the highest ranks, and such men were unafraid of tyranny or jealousy, and could make fortunes and achieve success without fearing their imminent execution. It was a great virtuous circle.
Commodus rather ruined this by his bad habit of killing those at the top. This meant that skilled men were lost and those who might have succeeded to their posts were reluctant to do so for fear of the same happening to them.
When Commodus was brought down, Pertinax succeeded him but was almost immediately murdered for trying to rein in the Praetorian Guard (despite the term being used today for politically loyal diehards, the Guard probably killed more emperors than it saved). Didius Julianus won the auction for the purple, only to be crushed by the ruthless Septimius Severus.
Severus, whilst not renowned as a bastion of morality, did restore some measure of stability after winning the civil war. But his eldest son was as bad as Commodus (Antoninus Caracalla, who discovered that repeatedly threatening to murder your own bodyguard and then unjustly killing his brother does not enhance one’s life expectancy). With the sad exception of Alexander Severus, the Empire underwent great tumult in the Crisis of the Third Century and never again [in the West] had the prosperity, stability, and power it had enjoyed in the Golden Age.
In short, Marcus Aurelius buggered it up by nominating as his successor a lunatic.
Henry II was an imperious king who ruled over England and substantial territories in what is today France. He also had the short-termist constitutional delinquency Blair had in meddling with lopsided devolution (which went from killing Scottish nationalism stone dead to an independence referendum in a couple of decades), and was thoroughly inept at running his own family.
Henry had two problems. He was a poor father and he had a weird feudal relationship with the king of France. Henry was king of England, but also held territories such as Normandy and Aquitaine. Problem was this meant he was, as lord of some of his territories, a tenant-in-chief who owed fealty to the king of France (in the same way the Earl of Norfolk owed fealty to the king of England).
This was a bugger’s muddle and no mistake, because if France and England went to war (which did, very occasionally, happen) the king of France could theoretically call on the king of England to serve him in the war against the king of England.
At the same time, the king of England was the full equal of the king of France, as sovereign of a kingdom.
Henry II fudged this in a masterstroke of ill-conceived ambiguity of which the EU would be proud. He swore fealty in vague terms only for the French lands, and parcelled the continental territories off to his sons (his eldest, also called Henry, got Normandy, Richard got Aquitaine, Geoffrey got Brittany, and John got nothing which earnt him the nickname Lackland. He later was so fearsome in war he got a second nickname: Softsword, possibly making him the only king in English history to have two epithets, both of which were mocking).
However, this is where the first problem, of weak fatherhood, comes in. All his sons were ambitious and he was neither able/willing to promise them what was their due, nor was he powerful enough to overwhelm them into submission. After Young King Henry (his son, who was given the title but not the authority of a king during the reign of Henry II) died, Richard, then eldest, wanted to be named heir.
You would’ve thought an eldest son in a feudal society being named heir would be straightforward. But Henry II refused. Ultimately, Richard did inherit (he became the Lionheart) but not before the brothers united to fight against their father. Philip Augustus, the wily French king, played this sort of game very well, exploiting familial rivalry to weaken Henry II and siding with the rebellious sons (this was repeated when Richard was away on Crusade/captured and John rebelled).
Henry II died relatively young, worn out by stress and exhaustion, most of it brought on himself. Richard inherited anyway, but the prime beneficiary of Henry’s foolishness was the French king. John later lost practically all the continental possessions (it turns out the nobles were unwilling to fight for a king whose prime achievements were extortion and cruelty).
By different turns, Marcus Aurelius and Henry II caused serious damage to their realms through failure of succession. Marcus Aurelius conferred the purple on a murderous maniac, and Henry II needlessly prevaricated with the simplest of acknowledgements, causing unnecessary war. Both in their power could have easily averted these crises, the former by sticking to the adoptive principle, the latter by taking the obvious step of naming his eldest son as his heir.
This does, however, highlight an important point. The family dramas of clashing personalities which can make a home fraught are not limited to those of humble station, and, in a time when monarchs exercised true power, these things could and did cause war within and between nations.