There’s a strange pattern among ancient monarchs and their dynasties. There never seems to have been a long series of great kings but a regular and predictable decline. Very rare was the dynasty that managed to last more than three generations.
The archetypal example is, of course, the principate in Rome. First we have Augustus, who seized power by force of arms but then created an image for himself as a man of peace. Not everyone liked Augustus or approved of everything he did, but respect and admiration for him was all but universal. Tiberius, on the other hand, started out well, but over time the pressures of ruling took their toll on him; he spent the last years of his reign relaxing in his pleasure palace at Capri and leaving the government of the empire to more interested men. Then came Caligula. After less than four years, the emperor’s uncle Claudius, whether through connivance or happenstance, saw his nephew shuffled off and took his place.
We can see here the pattern laid out. The founder of a dynasty has to run an effective propaganda campaign to consolidate the throne that he seizes by force. His son, however, lets the velvet glove grow thin, and the third in the dynasty proves to be some combination of tyrannical, incompetent, and insane. If the dynasty is lucky, as was the case with the Julio-Claudians, an uncle or cousin manages to seize power and keep rule in the family, but even in the best case that simply restarts the process.
The three-ruler scheme was not fixed: oftentimes things went faster. In Athens, the Peisistratids only lasted two generations. For his part, Peisistratus ruled quite well, at least after securing the tyranny for the third time. The farmers of Attica remembered his reign as “the age of Cronos,” referring to a golden age in Greek myth. Hippias and Hipparchus initially ruled much as their father had, but when the tyrannicides Harmodius and Aristogeiton murdered Hipparchus, his brother turned crueler. After a few years, the tyrant was ousted by a noble uprising backed by the Spartans. Hippias later plotted with first the Spartans and then the Persians to be reinstalled, but to no avail.
The Persian Achaemenids, strange as it may seem, followed the same pattern as their counterparts in the West. Cyrus the Great, whose name says it all, either inherited his empire from his grandfather Astyages or overthrew him, depending on whether one believes Xenophon or Herodotus, and established the Persian Empire throughout the Middle East. His son Cambyses conquered Egypt but developed a reputation for insanity almost to match that of Caligula. The third ruler, whose identity is unclear, didn’t last very long before Darius defeated him and assumed power.
(In connection to recent discussion concerning the absurd, Cambyses once mentioned to one of his advisors that people thought that he, Cambyses, was insane—no, really, they do—and said that he would prove the naysayers wrong. Cambyses pointed to a page, the advisor’s son, and said that he would shoot the boy right in the heart, which he proceeded to do. After doing the deed, Cambyses asked his advisor if he thought an insane person could have done such a thing. The advisor, wisely, praised the king’s aim and then plotted a coup … which succeeded.)
The cause of this progression seems to lie in the lifestyle of a king and his immediate family. In order to establish his dynasty, the founder has to be skilled at both warfare and diplomacy: if he can’t defeat his enemies, he won’t become king in the first place, and if he can’t mollify his subjects, they won’t put up with him for very long. The first king has to struggle first to attain power and then to hold it.
The second generation, however, does experience the same challenges. The great king’s heir does not have to struggle for power in the same way that his father did. For him, power is a given; people bowing and scraping before him is normal. His father makes sure that he is educated in the skills he will need to rule, but he is still not truly ready for the stresses of governing. If he has the right innate qualities, he can do great things, like Xerxes or Periander of Corinth did; otherwise he’s likely to grow tired of being nice to people he hates and either retire or start killing them.
The third ruler in the dynasty is likely to have such contempt for his subjects, or at least for the elites with whom he has to work on a regular basis, that he would rather just kill them and enjoy himself than rule constructively. If his predecessors were effective, he will be in a position to do this; if they were not, he is likely to be a mere puppet of an elite clique. In either case, someone is going to get upset enough to kill him before very long, either one of his subjects who doesn’t like being terrorized or one of his family members who doesn’t want the dynasty run into the ground.
But, but, you say, what about the Five Good Emperors? If we include Commodus, that “dynasty” lasted for six generations before being overthrown. How did they manage to defy the laws of power for so long?
To understand the success of this dynasty, let’s look at how it ended. All things considered, Commodus wasn’t a particularly bad ruler: he kept the barbarians at bay; he crushed a few rebellions; he stopped persecuting Christians. However, he personally disengaged from ruling after a time and insofar as he did actively rule, his aim was to concentrate power in his own hands and to diminish the influence of his father’s supporters. His disengagement led to political chaos as lesser imperial officials competed for power, and his efforts at centralization reduced the benefits that the senatorial class derived from the imperial government. Commodus’ well-known antics also emphasized that he personally was the center of power. The emperor ruled, and the emperor’s favorites benefited, but the rest of the elites were left out in the cold. These elites were not about to take such an assault on their interests lying down and so murdered Commodus.
Commodus thus fits the bill for a ruler of the second generation, which makes sense considering that he was the biological son of the previous emperor. Marcus Aurelius presumably trained his son to rule after him and did the best he could, trusting that the same upbringing that shaped him into an excellent ruler would work on the next generation.
Indeed, though Marcus Aurelius had not been born to the purple as Commodus was, he had been raised to be emperor since he was barely a man. Before being adopted by Antoninus Pius, Marcus Aurelius was expected to become an imperial bureaucrat; after, he had a great deal of time to learn the ropes under an especially competent and long-lived emperor.
Although Marcus Aurelius is often blamed for breaking with precedent and choosing his own biological son to succeed him, it was a reasonable extrapolation from his own experience. For his part, Antoninus Pius had adopted Marcus Aurelius, along with Lucius Verus, simply to help smooth his own succession to Hadrian, and given the differences between Aurelius and Verus, Antoninus’ influence seems to have been less important than the two men’s early upbringing. Marcus Aurelius might have reasonably assumed that the way to raise good emperors was to get to them while they were young.
The practice of succession by adoption which typified Five Good Emperors was in fact adopted for precisely the purpose to which Antoninus Pius had put it: making succession go more smoothly. After the assassination of Domitian (another second-generation emperor), the Senate chose Nerva to serve as emperor. This was a very shrewd choice: Nerva had been a close ally of Domitian, so there would not be a major reshuffling of imperial offices, but he was also old and childless. Nerva’s job was to choose a successor who could rule effectively but still be agreeable to the Senate. He accomplished this by selecting Trajan, who went on to become the archetypal Roman emperor.
Trajan may or may not have adopted Hadrian, but the Senate found him acceptable regardless. Hadrian only designated Antoninus as his heir at the very end of his life. Indeed, it appears that bad dynastic luck was the major factor causing emperors to adopt their heirs: they simply didn’t have sons of their own, at least, not until Marcus Aurelius.
(As an aside, the imperial bureaucracy that produced Nerva and provided heirs for the Good Emperors grew out of another pattern of ancient monarchies. The founder of the first dynasty establishes a royal administration that operates separately from, but not completely independent of, the preexisting power structure. If the kingship lasts one cycle, the founder of the next dynasty will refine the bureaucracy in order to make it more efficient. Examples of this include Darius I, Claudius, and Henry II.)
By the High Middle Ages things had changed: whereas the position of a dynasty in antiquity was generally quite precarious, hereditary feudalism strengthened the position of a monarch, at least as a monarch. Providing fiefs, essentially outsourcing the government of various territories, allowed a king to become the nominal ruler of a very large territory without necessarily having effective control over it; thus, if a king was weak, his nobles would ignore him rather than overthrow him.
Making fiefs, including the kingship, hereditary also strengthened the dynasty. To attempt to overthrow a hereditary king undermines the principle of hereditary rule by dukes and counts and barons as well. In England, the nobles only resorted to such an extreme measure when King John proved totally intractable, and they dropped the idea before his corpse was cold. In the Holy Roman Empire, where elective kingship survived, revolts against royal authority were much more frequent and severe.
The relative security of medieval kings damped the cycle of decline. In England, for instance, the Norman dynasty survived quite comfortably until Henry I died without male issue and Stephen of Blois seized the throne. Even then, the civil war that followed Stephen’s accession and led to the installation of the Angevin dynasty was a conflict within the royal family. Indeed, with the exceptions of William III and George I, and of course the Commonwealth period, William the Conqueror and his descendants have ruled England since 1066.
In the Islamic world, a similar cycle recurred. Muslim scholar Ibn Khaldun noticed the following pattern in royal houses: the founder of a dynasty would be a desert nomad who led his people forth to conquer city-dwellers, but once in power, the new rulers would deteriorate in quality (and asabiyah, Khaldun’s own term, would likewise decline) to be overthrown by another group of desert nomads in the fourth generation.
So, what are some lessons we can draw from all this history? Our interest in the past isn’t merely antiquarian, after all: we want to learn from it. I propose the following four:
- Monarchies decline over the generations. There is nothing that can stop this process permanently, but certain social technologies can be deployed to slow the process and mitigate its effects. In the absence of these technologies, a dynasty can be expected to last only two or three generations before being replaced.
- Royal government must be broadly inclusive of elites. Even if power is de jure quite concentrated, dissatisfied elites will stage rebellions and coups which, even if unsuccessful, will distract the king from constructive government. At the same time, royal government must be royal—elites cannot be given free reign, lest their squabbles for power produce chaos. The king must find the middle way between being a figurehead and being a despot.
- The most secure monarchy has the same principle of legitimacy as the elites. If the elites are land-owning warriors, the king should be land-owning warriors; if the elites are priests, the king should be a priest; if the elites are bureaucrats, the king should be a bureaucrat.
- Biological succession is a Schelling point. Adoptive succession produces superior results by avoiding the deleterious effects of royal upbringing, essentially restarting the dynasty each generation, but it requires that the king not have children. Elective succession is a recipe for revolt.