Empire of Silence definitely shares DNA with the works I mention here. The biggest political union in the thoroughly human-settled galaxy (our good old Milky Way) is an Empire that House Corrino would find familiar, complete with a Landsraad of aristocratic families, some of ancient lineage (we learn in the appendix to EoS that our hero's family claims descent from the British royal family we 21st century types know and thumb our noses at), some gotten up robber baron types who bought their way into the nobility by time honored atrocities like slave trading, and planetary populations enjoying various levels of material comfort on terraformed worlds of varying quality. And yes, there is a coveted and vital substance that holds the Sollan Empire and its neighboring republics and federations together in a plural galactic civilization, but it's nothing we 21st century types would regard as exotic or semi-magical, it's just good old Uranium.
So, nobody is going to metamorphose into a giant worm or anything, nor is anyone exhibiting supernatural or superhuman abilities like prophecy or telepathy. The highest class, the Palatinate (lots of echoes of the Roman Empire in the Sollan) has benefited from millennia genetic engineering and breeding and enjoy extraordinary attractiveness, health, height and life-spans, but it's just science.
Our hero, Hadrian Marlowe, is the elder son of a mid-level planetary noble and the grandson of that planet's hereditary ruler, but as we get to know him on his home world of Delos, we see that he's neither his father's favorite to succeed nor is he exceptionally interested in doing so; he's more inclined to scholarship than politics or diplomacy, and only undertakes the rest of his training out of a sense of duty to the people who would otherwise someday be ruled by Hadrian's younger brother, who exhibits the martial temperament and bloody-mindedness that people expect of a ruler but has a cruel streak and a seeming disinterest in anything that isn't fighting or fucking.*
But when Hadrian takes a diplomatic matter somewhat into his own hands, unbidden, and makes a hash of it, his father decides to ship him off to the Chantry, the rigid religious order that generally seems to exercise greater power in the Sollan Empire than the Emperor and nobility do, and name Hadrian's brother as heir.
Only Hadrian wouldn't be a monk so much as... a torturer; the Chantry enforces orthodoxy the nasty, Inquisitional way. And like I said, Hadrian is more of a scholar than a religious zealot.
The main plot of Empire of Silence, then, is what happens after Hadrian, his tutor and his mother hatch a plot to escape this fate, and what goes spectacularly and fascinatingly wrong with their plans.
The galaxy we begin to explore with Hardrian proves to have a bit more diversity than we ever saw in the Herbertverse; in addition to human societies who owe no allegiance to the Empire, there are other species, though only one of them has attained space flight and reached out into the cosmos. More about them in a bit. The rest of the species humanity has encountered have been less technologically and (apparently, presumably) culturally advanced and you can probably guess what that has meant for them; colonization and, usually, enslavement. Thus a mysterious alien race native to the backwater planet where Hadrian winds up for most of this novel are reduced to manual labor and subservience and are considered by most to be little more than animals, though a few scientists have continued to study them, their unique modes of consciousness, and their means of communication. But these scientists are not Sollan Empire citizens and are themselves regarded with suspicion and hostility by their hosts, who all adhere to the rigid doctrines of the Chantry, which, OK, let's talk about the Chantry, for it is where the Sun Eater series most differentiates itself from the Herbertverse or the Solar Cycle.
The state religion of the Sollan Empire feels extremely and uncomfortably familiar because it's basically the settler-colonialist mentality as holy writ. Humanity has a Manifest Destiny to own and control the entire galaxy, maybe eventually the entire universe; any other races it encounters must be subjugated for their own good (and, of course, the good of their human masters). All the stars and all the planets and all the rocks and cosmic dust in between are there for humanity's use. Refreshingly, though, there is no messiah figure or religious narrative (at least not as appearing in this first novel); the object of worship is nothing more, nothing less, than the mother planet, Earth, which we've lost track of in our rush to expand and expand. Maybe it's a myth? But don't say that aloud, because the Chantry will get you and punish you as a heretic. Oh, and the Chantry has elements of Dune's Butlerian Jihad, too: cybernetic implants, artificial intelligence, etc are absolutely banned. Thou shalt not make a machine in the likeness of a human mind, etc.
So yes, there is a lot of world-building going on in this first novel, but, refreshingly, it never feels like the reader is getting info-dumped upon. Hadrian is a fine narrator of his experience and incorporates all of this exposition very naturally into his story -- and he hooks us in right away by revealing, right at the very beginning of the book, that his long, long life (spanning thousands of years, though he's only something like 18 years old when he leaves Delos) has made him famous to some, infamous to others. In pursuing peace with an enemy I haven't mentioned yet, he has been forced by circumstances we're not going to get to know much about in this first novel to destroy an entire inhabited star system. Hadrian is the Sun Eater of this series' title.
Lordy do I love a villain-hero, almost as much as I love an unreliable narrator, though I'm not sure that Hadrian is the latter. His narrative voice is introspective, honest about his faults and failures, anxious about his shortcomings, guilt-ridden, self-critical, all the things that the genre reader's favorite unreliable narrator, Severian, much more concerned about justifying himself and persuading us that he is a really good guy and irresistible to women, etc. is not. Hadrian doesn't care what we think of him; indeed, is resigned to never being able to improve or alter the opinion of him his imagined readership is understood to have already. Sun Eater is no apology, nor is it a parable. To diminish it a little, I could compare it as justifiably with something like Piers Anthony's Bio of a Space Tyrant as with Dune or Book of the New Sun. It's big and sprawling and ambitious as hell, but it's not set before us as a puzzle to solve or a tractate on What is Humanity; it's just a great big story of great big events with lots of action, emotion and satisfying character relationships. And a few mysteries, starting with pretty much everything about the only other spacefaring race in the galaxy, the Cielcin, with whom humanity has come into armed conflict over territory, and what, if any, the Cielcin's and some of the other subjugated species relationship might be to a dead civilization that has left mysterious and sophisticated ruins on many of the worlds to which Humanity is the Johnny-Come-Lately.
I haven't even gotten into the other characters sharing Hadrian's journey but this is getting long and my hands are seizing up (I can't use Dragon Naturally Speaking very well in the summer because the only way my attic office is bearable is with a loud old swamp cooler noisily rattling day and night, so I'm actually having to type this!). But there are some wonderful ones, a beggar girl who rescues and befriends Hadrian when he washes up on the backwater planet of Emesh instead of the planet-sized university analogue he thought he was traveling to, friends beside whom Hadrian fights as a gladiator, courtiers in the palace of the parvenu nobility who eventually yank Hadrian out of the arena, and the aforementioned foreign scientists from other polities who don't truck with hereditary nobility or Manifest Destiny or banning cybernetic implants and who expand Hadrian's mind.
And, by the way, these are men and women and there don't seem to be gender roles as such in Sollan society? A gladiator or a planetary ruler or a Grand Inquisitor or a scientist can be either, and it's no big deal. And at least one of the alien species seems not to have sex or gender at all that we can determine so far, and that's also no big deal except occasionally grammatically as Hadrian tries to wrap his head around their not-quite-language to better understand them. And it's these elements as much as anything that make me not mind the neo-feudalism, and want to continue through this whole series and its several sidequels, which I will continue to enjoy in audio form because the narrator (who seems to be in for the entire run), Samuel Roukin, simply is Hadrian. I first encountered him in the American Revolutionary War TV drama Turn, in which he played the insufferable redcoat villain Simcoe, and it's impossible not to imagine Roukin as Hadrian himself in the movie in my head. Roukin gives Hadrian just the right combination of aristocratic self-assurance, self-criticism and wonder, though I wish he'd cut back on the Shatnerian pauses in the middle of phrases, which are not merely annoying but at times interfere with comprehension because Ruocchio is not a great user of dialogue tags, meaning that sometimes what starts of sounding like mere narration is actually someone's dialogue and not necessarily Hadrian's. But I quibble. As I said, Roukin is Hadrian, and I'm already diving into the direct sequel to EoS, Howling Dark. The title alone is irresistible and makes me think, of course, of Alastair Reynolds and his Inhibitors. Arooooo!
*We get hints that there might be more to this brother than we or Hadrian give him credit for, and he gets a spin-off novel that I'll have a look at when I'm through the main series.