Some writings on the souring of the entire mood of Roman culture following the 3rd century crisis. Certainly of inspirational value for the grim darkness of the far future. After all, how did it turn grim in the first place?
Speaking of the jaded Imperium Romanorum, a parallel process happened with its high culture, as described by Thersites at the very end of this video:
"The Roman empire would eventually recover from the third century crisis and go on to last a couple of hundred more years, but it was never really the same. It was never as vibrant. It was never as powerful as before. And also, a lot of its traditional culture had been lost, and would never really be recovered.
To give but one example: Rome had largely been fairly easy-going when it came to sexuality for most of its history. But after the third century crisis, Roman writers are very prudish, very judgemental, very uncomfortable with sexuality. They also tend not to have much of a sense of humour, if any. Almost all the Roman literature, and I guess also all the Greek literature from the Roman period, that occurs after the third century crisis, is very bitter. It’s acrimonious. It’s not fun. There’s no life in it. The scholarship becomes very stilted, very backward-looking.
Rome just really isn’t the same, and it’s hard to explain if you haven’t dealt with the material in great detail. Just the fundamental mood of Rome, the fundamental mindset just goes through a major shift after this fifty year crisis. In many ways, you can argue that, for all practical intents and purposes, the Roman empire ends with the third century crisis, and the middle ages begin."
I can support this view based on my own readings. Ammianus Marcellinus is interesting, but he never ignites laughter. Procopius is likewise largely bereft of humour, despite thrilling material. Suetonius, in contrast, offers plenty of gossip fun and jokes, having Augustus quote the Illiad’s lines for a spear-waving hero upon seeing a well-endowed dockworker, or immortalizing this rhyme on the building of Nero’s golden palace following the great fire of Rome:
“The palace is spreading and swallowing Rome,
Let us all flee to Veii and make it our home.
Yet the palace is spreading so damnably fast,
That I fear it will gobble up Veii at last.”
Even the dry Tacitus will sometime skewer someone with his sharp pen. On Galba: “He was a man whom everyone thought would have made for a good ruler, if he had not ruled.” The later Roman stuff makes for more boring reading.
This draining of fun from the culture helps explain emperor Julian’s self-deprecating humour in the Misopogon (the Beard-Hater), which did not find any takers at all in such a humourless age, least of all in the very Christian city of Antioch. The bookish Julian was refreshingly out of sync with his own times. Filled with the enterprising energy and vigour of high antiquity, he modelled himself on classical Greeks and Romans. Julian wanted to revive both paganism and Augustus’ Principate, and sought to tear down the stilted and openly autocratic Dominate established by the nigh-on totalitarian Diocletian. To Julian, the emperor should be accessible and approachable, the first citizen among theoretical equals, and able to both take and give jokes, quips and puns. Just as had been the case before the crisis of the third century, before humour withered amid severity.
Speaking of traumatized empires in decline, refusing to die against all the odds in the face of overwhelming enemies, the last Roman-Persian war of 602-628 is yet another piece from late antique and medieval Roman history that is of high interest for fictional 40k worldbuilding.
In it, we see what some have nicknamed the first crusade as the cornered Roman empire became fired up with religious zeal in a fanatical outburst, in response to the True Cross being taken from Jerusalem by the Sassanid conquerors. We also see a decaying empire falling apart following the failed reign of Phocas and Byzantine infighting (as contrasted to the militarily competent rule of Mauricius just a few years earlier), with swathes of territory being lost to the Persians.
With the Shahanshah ascendant, Constantinople itself was cornered by Avars and Slavs on the Thracian side, and a Persian army on the Anatolian side of the Bosphorus. The defenders of New Rome managed to hold out in the face of overwhelming odds, and they sank Persian vessels attempting to ferry over siege machines. The Walls of Theodosius held firm, while the Patriarch of Constantinople filled the troops with determination and fervour by his zealous speeches.
Even as the capital was surrounded, the Roman field army could not afford to intervene. The Roman empire was broke, and so the church sold off all silver to pay for the elite training of the last Roman army on earth. In a daredevil strategic move, emperor Heraclius landed in the Caucasus and struck deep into Persian core territory, torching the most sacred Zoroastrian fire temple of Adur Gushnasp and beating army after army sent to destroy his force. Finally, with Turkic assistance, the Romans won the war outside the ruins of Nineveh, the ancient capital of feared Assyria.
The bold strategy of a cornered emperor had worked against all the odds, and a combination of zealous fanaticism, Roman military professionalism, luck and skilled command of armies had saved the Roman empire from obliteration. A triumph was held in Constantinople to celebrate the great victory. Shortly thereafter, Roman dominions in Syria and Egypt were lost to Arab invaders, while the same rising power simultaneously managed to conquer the entire Sassanid empire.
Definite interest to 40k: A bitter age, with bittersweet victories amid so much decay and dysfunctionality, set to the tone of religious fervour and stark desperation.
