Books like 'Citadel'

Readers who enjoyed Citadel by Marko Kloos also liked the following books featuring the same tropes, story themes, relationship dynamics and character types.

sc-fi space action / adventure military, war & conflict space-opera war military space-travel galactic-empire soldiers

Stand Alone: Wolfhounds - Book One by John Van Stry
Rated: 4.59 of 5 stars
· 11 ratings
Chase had it all planned out, do a little time in one of the emperor's jails, say a four year stretch for getting rid of some trash that no one would miss, and when he got out, the path to the leadership would be wide open...

Categorized as:
military space-opera soldiers galactic-empire space-fleet sci-fi action-adventure fiction
Livesuit by James S.A. Corey
Rated: 4.33 of 5 stars
· 18 ratings
Humanity's war is eternal, spread across the galaxy and the ages. Humanity's best hope to end the endless slaughter is the Livesuit forces. Soldiers meld their bodies to the bleeding edge technology, becoming something more than human for the duration of a war that might never end.The first novella set in the universe of James S. A. Corey's epic Captive's War series...

Categorized as:
space-opera war military soldiers space-fleet sci-fi fiction audiobook
The Price of Liberty by D.J. Holmes
Rated: 4.50 of 5 stars
· 10 ratings
War has been declared. The Indian Star Republic has landed ground troops on the newly discovered colony of Haven as they seek to seize access to the alien worlds of Vestar and Kulthar. The British Star Kingdom has reacted. A battle fleet has been formed with orders to drive off the Indians and retake Haven...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel war action-adventure
Turning Point by Jason Anspach, Nick Cole
Rated: 4.53 of 5 stars
· 20 ratings
Fight to Win. With the galaxy in turmoil, the Legion initiates Article Nineteen, a hard reset designed to halt the corruption and ineptitude that continues to spill forth from the Galactic Core. But when the House of Reason aligns itself with the bloodthirsty zhee extremists, the Legion has no choice but to commit to a savage campaign of Total War...

Categorized as:
galactic-empire military soldiers space-fleet space-opera war action-adventure adult
Rescue The Princess by John Hindmarsh
Rated: 4.42 of 5 stars
· 12 ratings
Jack suffered from an attack by the Blue Caps. He sued the RSN and won. He also sued the Royal Family and won. Now he’s acquired his own warship and his first mission is to rescue the princess.What? Yes, Sofia is missing. The Queen has taken an intense dislike to her daughter’s ambitions and Sofia has disappeared. Jack sets out to rescue her with the assistance of Black Company marines...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Fortitude by Glynn Stewart
Rated: 4.42 of 5 stars
· 12 ratings
An offer that no one else could matchA mission that no one else could achieveAn enemy only a few know they share…Commodore Kira Demirci is now the commander of a small but powerful mercenary force—one of the most dangerous in the cluster of stars she now calls home. Her own actions have brought peace to the Syntactic Cluster, though, and a mercenary is in limited demand...

Categorized as:
military space-opera galactic-empire soldiers space-fleet sci-fi action-adventure fiction
Echoes in the Deep by J.N. Chaney, Terry Maggert
Rated: 4.67 of 5 stars
· 6 ratings
Mark Tudor is learning a valuable lesson about being a Peacemaker.With Veteran pay comes veteran problems. And the Guild, more often than not, is the issue.He’s become an effective enforcer of the law, but unfortunately, crime is growing a lot more complicated...

Categorized as:
space-fleet soldiers military galactic-empire sci-fi action-adventure space violent-conflict
Foundations of Glass by J.N. Chaney, Terry Maggert
Rated: 4.67 of 5 stars
· 6 ratings
The road between the stars was paved in platinum ore. But as Mark Tudor is about to learn, the cost of justice is paid in blood.And no one is truly safe.Gyl Mareth’s Rot corrupts the Guild, and Mark means to cut it out at the source. To do that, he’ll have to lobby powerful supporters—spindly, blue aliens, toads infatuated with buearcracy, and maybe even an influential bartender or two...

Categorized as:
soldiers galactic-empire military space-fleet sci-fi action-adventure space violent-conflict
Buccaneers by Jamie McFarlane
Rated: 4.43 of 5 stars
· 23 ratings
The crew of the Hotspur just happens to be looking for a new home. If Nick James is right, and he usually is, the Tipperary solar system is about to become the busiest trading hub in the galaxy. To sweeten the pot, the cloud-city of Lèger Nuage is offering free warehouse space to qualified traders. It's a deal that seems too good to pass up. Of course, nothing's as simple as it seems...

Categorized as:
military soldiers space-fleet space-opera space-travel war action-adventure adult
Prisoners of Darkness by Jason Anspach, Nick Cole
Rated: 4.46 of 5 stars
· 21 ratings
The galaxy is spiraling into all-out war. The Battle of Tarrago was just the beginning. Following Goth Sullus's ruthless onslaughts against the Republic, a desperate House of Reason searches for scapegoats—and finds one, deserving or not, in Commander Ellek Owens. His sentence is cruel, unjust—and final. Unless Victory Squad has anything to say about it...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel war action-adventure
Darkness Beyond by Glynn Stewart
Rated: 4.41 of 5 stars
· 24 ratings
A newly-founded human colony world burned from orbit A warship squadron of the galaxy’s oldest race ambushed and destroyed An ancient enemy reborn in the darkness beyond the known stars The A!Tol Imperium and their new human subjects have had fifteen years of relative peace. New colonies have been founded, new worlds explored, new ships built...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel war action-adventure
Galaxy's Edge: Takeover: Season Two: Book One by Jason Anspach, Nick Cole
Rated: 4.50 of 5 stars
· 8 ratings
Every disaster brings an opportunity. Goth Sullus and his empire have fallen. With the Legion and the rest of the galaxy watching from the still-smoldering galactic core, Carter, a former legionnaire turned private contractor, and Jack Bowie, a Navy spy with nowhere left to turn, sign up to work for an enterprising private contractor looking to make a statement on the planet Kublar...

Categorized as:
military soldiers space-fleet space-opera war action-adventure adult aliens
Star Force: Excalibur by Aer-ki Jyr
Rated: 4.50 of 5 stars
· 8 ratings
The Zak'de'ron take note of the Rit'ko'sor joining Star Force, making contact and making their wishes known...but in the process they make a critical mistake that will forever alter their relationship with the trailblazers...

Categorized as:
galactic-empire military soldiers space-fleet space-opera action-adventure adult aliens
Rimward Stars by Glynn Stewart
Rated: 4.39 of 5 stars
· 24 ratings
A helpless ally calls for aid A ruthless enemy strikes without mercy The fate of empires turns on even the smallest actions When a minor trade partner sends the Castle Federation a desperate call for aid, they have few resources to spare from their all-consuming war against the Terran Commonwealth...

Categorized as:
galactic-empire military soldiers space-fleet space-opera war action-adventure adult
Survivors by Toby Neighbors
Rated: 4.40 of 5 stars
· 10 ratings
Nothing in the Corps is guaranteed!Staff Sergeant Eli Vanhorn isn’t the man he used to be. Once a proud member of the Fleet Marine Corps’ elite Terrestrial Advance Combat teams, the battle on colony planet Luyten C left him broken and scarred. But after a year of surgeries and physical therapy, he’s ready to complete his enlistment as Master of Arms on the exploration vessel Rihla...

Categorized as:
galactic-empire military soldiers space-fleet space-travel war action-adventure aliens
Equilibrium by Glynn Stewart
Rated: 4.40 of 5 stars
· 10 ratings
Peace forged on the edge of civilizationLies forged in the heart of mankindA legend rises to the final challengeExile to the Syntactic Cluster has been good for Kira Demirci and her friends. Once elite pilots of the Apollo System Defense Force, they now own the most powerful mercenary warship in the entire star cluster...

Categorized as:
galactic-empire military soldiers space-fleet space-opera war action-adventure adult
Galactar by Anthony James
Rated: 4.40 of 5 stars
· 10 ratings
Following decades of war and the recent catastrophic loss of an entire planet, the Human Planetary Alliance is riven by internal disputes and rivalries. The military’s old guard fights for power against those who see a chance to turn things around.After a series of hard-fought victories, Captain Carl Recker is becoming recognized as a man who gets results - a man who knows how to beat the Daklan...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Star Force: Origin Series by Aer-ki Jyr
Rated: 4.40 of 5 stars
· 10 ratings
The Origin Series is empire building at its finest, with 100 episodes and over 2.5 million words in the military science fiction serial detailing the rise of Star Force from corporate entity into an interstellar empire over the course of more than a millennium...

Categorized as:
galactic-empire military soldiers space-fleet space-opera action-adventure book colonization
Star Force: Origin Series by Aer-ki Jyr
Rated: 4.40 of 5 stars
· 10 ratings
The Origin Series is empire building at its finest, with 100 episodes and over 2.5 million words in the military science fiction serial detailing the rise of Star Force from corporate entity into an interstellar empire over the course of more than a millennium...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Fulcrum Gun by Anthony James
Rated: 4.40 of 5 stars
· 10 ratings
Lost in hostile space and pursued by the most powerful warship in the known universe, Captain Carl Recker is losing hope and running out of options. His battleship Fulcrum is no match for this enemy and the Meklon aliens who might have helped him are dead, killed by the Galactar’s murderous weaponry.Somehow, Recker must find a way to succeed where the might of an alien empire already failed...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Laws of Ancidium by Anthony James
Rated: 4.40 of 5 stars
· 10 ratings
Having fought his hardest battle, Captain Carl Recker returns to planet Lustre, bringing the alien battleship Fulcrum with him.Recker is under no illusions that he’ll be offered backdated shore leave, but his feet don’t even touch the ground before trouble shows up. A heavily armed fifty-thousand-metre Meklon interstellar drops out of lightspeed near the planet...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Return to Haven by D.J. Holmes
Rated: 4.40 of 5 stars
· 10 ratings
The revelation that the human race is not alone has sent shockwaves throughout Earth’s naval powers. Suddenly all eyes have turned to Haven and the trade routes to the Vestarian and Kulrean homeworlds. Thinking he has nothing to lose, Haven’s First Councilor puts into motion a plan that threatens to turn star empire against star empire...

Categorized as:
military soldiers space-fleet space-opera space-travel war action-adventure adult
Archangel Rising by Evan Currie
Rated: 4.39 of 5 stars
· 23 ratings
Archangel Squadron faces off against the forces of the brutal Protectorate to claim a prize, and save humanity, in a gripping novel of deep space jeopardy by the author of the Odyssey One series. At the helm of a commandeered freighter, Captain Steph Michaels has infiltrated the Free Star systems...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel war action-adventure
Relics of Eternity by Glynn Stewart
Rated: 4.33 of 5 stars
· 12 ratings
The edge of Imperial expansionFar from Earth and the other homeworldsHere lie the secrets of ancient godsHere…there be dragonsSeeking to escape the shadow of Annette Bond’s success, Captain Morgan Casimir has taken a posting on the far side of the A!Tol Imperium. Here, she hopes to begin a legend for herself that stands apart from her stepmother the Duchess...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel war action-adventure
Raven's Peace by Glynn Stewart
Rated: 4.31 of 5 stars
· 13 ratings
Ten thousand stars, once chained, taste freedom An eternal empire, once undefeated, falls to pieces An alliance, once united, now lacks a common foe War was hard enough. Peace may be impossible For seventeen years, Colonel Henry Wong and the United Planets Space Force have fought the Kenmiri Empire...

Categorized as:
galactic-empire military soldiers space-fleet space-opera war action-adventure adult
The Others by Jay Allan
Rated: 4.46 of 5 stars
· 17 ratings
From the deepest darks of unknown space, evil comes… Admiral Tyler Barron and the Confederation navy face a new threat, darker and deadlier than any that have come before...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel war action-adventure
Ballistic by Marko Kloos
Rated: 4.20 of 5 stars
· 20 ratings
There is a personal price to pay for having aligned with the wrong side in a reckless war. For Aden Jansen it’s the need to adopt a new identity while keeping his past hidden. Now he’s integrated himself aboard the Zephyr, a merchant ship smuggling critical goods through dangerous space. But danger is imminent on planet Gretia, as well...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel war action-adventure
Judas Kiss by Rick Partlow
Rated: 4.50 of 5 stars
· 6 ratings
The battle for Sparta has begun. Logan Brannigan has taken back his father’s name and now he and Wholesale Slaughter fight to reclaim his father’s throne. But deposing the traitor, Rhianna Hale, without bringing all of Sparta into a bloody and divisive civil war won't be easy. And while the Spartans fight among themselves, vultures circle, waiting for their chance to claim what’s left...

Categorized as:
galactic-empire military soldiers space-fleet space-travel action-adventure adult book
Star Force: Phoenix by Aer-ki Jyr
Rated: 4.50 of 5 stars
· 6 ratings
Cal-com's journey is not at an end. In fact, it's just beginning..

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Third Moon Chemicals: Adventures of a Jump Space Accountant Book 3 by Andrew Moriarty
Rated: 4.50 of 5 stars
· 6 ratings
Jake's back. He's not the best spy ever. He fails his pilot exam, he can't shoot, and he gets beat up a lot, usually by girls. Next task is to track containers of missing food. What could possibly go wrong? Next thing he knows he's on a strange ship with not one, but two pretty girls, helping them smuggle illegal workers to pirates...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Dead Man's Debt by Elliott Kay
Rated: 4.29 of 5 stars
· 28 ratings
“WE REQUIRE A DIFFERENT BATTLEFIELD.” Nobody expected the war to last three hours, let alone three years. The star system of Archangel holds the line against invading corporate fleets, but a quarter of its territory is already lost. The navy can’t hang on much longer. Faced with this grim truth, Archangel’s leaders shift their strategy to diplomacy and espionage...

Categorized as:
military soldiers space-fleet space-opera war action-adventure adult audiobook
The Complete Hammer's Slammers Volume 3 by David Drake
Rated: 4.38 of 5 stars
· 8 ratings
With a veteran ’s eye for the harsh and gritty details of war, David Drake depicts a futuristic analog of Vietnam-era tank combat in his Hammer’s Slammers fiction. Upon this tactical foundation, Drake uses historical metaphor to provide a rich and detailed future-history that is both unique and strangely familiar...

Categorized as:
military soldiers space-opera space-travel war action-adventure adult anthologies
Terminus Cut by Rick Partlow
Rated: 4.38 of 5 stars
· 8 ratings
Mercenaries with a mission. Logan Conner has given up the life of a warrior prince to become Jonathan Slaughter, a mercenary captain of a rough-and-ready band of mech-jocks for hire. Already legendary throughout the Periphery, their next job brings them head-to-head with the Jeuta, militant aliens who seek to loot and plunder isolated human colony worlds...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel war action-adventure
Evasion (Scattered Stars: Evasion Book 1) by Glynn Stewart
Rated: 4.38 of 5 stars
· 8 ratings
A captain on the run from the horrors of his pastA girl on the run from the trap of her presentA ship that will bring them togetherCaptain Evridiki “EB” Bardacki was once a nova fighter pilot for a nation he truly believed in. Betrayal and failure sent him into exile and flight...

Categorized as:
galactic-empire military soldiers space-fleet space-opera action-adventure adult book
Star Force: Origin Box Set #93-96 by Aer-ki Jyr
Rated: 4.38 of 5 stars
· 8 ratings
The Origin Series is empire building at its finest, with 100 episodes and over 2.5 million words in the military science fiction serial detailing the rise of Star Force from corporate entity into an interstellar empire over the course of more than a millennium...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Star Force: Origin Series Box Set (85-88) by Aer-ki Jyr
Rated: 4.38 of 5 stars
· 8 ratings
The Origin Series is empire building at its finest, with 100 episodes and over 2.5 million words in the military science fiction serial detailing the rise of Star Force from corporate entity into an interstellar empire over the course of more than a millennium...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Star Force: Origin Series by Aer-ki Jyr
Rated: 4.38 of 5 stars
· 8 ratings
The Origin Series is empire building at its finest, with 100 episodes and over 2.5 million words in the military science fiction serial detailing the rise of Star Force from corporate entity into an interstellar empire over the course of more than a millennium...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Star Force: Origin Series by Aer-ki Jyr
Rated: 4.38 of 5 stars
· 8 ratings
The Origin Series is empire building at its finest, with 100 episodes and over 2.5 million words in the military science fiction serial detailing the rise of Star Force from corporate entity into an interstellar empire over the course of more than a millennium...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Star Force: Origin Series by Aer-ki Jyr
Rated: 4.38 of 5 stars
· 8 ratings
The Origin Series is empire building at its finest, with 100 episodes and over 2.5 million words in the military science fiction serial detailing the rise of Star Force from corporate entity into an interstellar empire over the course of more than a millennium...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Star Force: Origin Series by Aer-ki Jyr
Rated: 4.38 of 5 stars
· 8 ratings
The Origin Series is empire building at its finest, with 100 episodes and over 2.5 million words in the military science fiction serial detailing the rise of Star Force from corporate entity into an interstellar empire over the course of more than a millennium...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Red Team Alpha by Jay Allan
Rated: 4.38 of 5 stars
· 8 ratings
A New Adventure Set in the Crimson Worlds Universe (Over 800,000 Crimson Worlds Book Sold) Red Team Alpha. An elite military unit. Twenty highly-trained veteran warriors, Mars’ best. They are ready to face whatever dangers threaten the Confederation. They are capable, dedicated, armed with the best technology Mars has to offer. And they don’t exist, at least not officially...

Categorized as:
galactic-empire military soldiers space-fleet space-opera war action-adventure adult
Inferno Sphere by Anthony James
Rated: 4.38 of 5 stars
· 8 ratings
Inferno Sphere. A bomb to end all bombs. The ruthless species of biomechanical aliens known as Vraxar have been driven away from the Confederation planet Atlantis. They are not defeated and their unprovoked attack has given them the means to locate the rest of the Confederation worlds. However, the Vraxar are not predictable and their next move is completely unforeseen...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Empires in Ruin by Anthony James
Rated: 4.38 of 5 stars
· 8 ratings
Protected by their energy shields, the Lavorix warships Aeklu and Verumol survived the largest explosion ever created by technology. Now salvaged by the Human Planetary Alliance and their new Daklan allies, these once unstoppable weapons of mass destruction sit in a construction yard undergoing extensive repairs...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Star Force: Ysalamir by Aer-ki Jyr
Rated: 4.38 of 5 stars
· 8 ratings
V'kit'no'sat and Star Force must unite for a special project in order to find a better way to fight the Hadarak...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure aliens
Cyborg Legacy by Lindsay Buroker
Rated: 4.33 of 5 stars
· 22 ratings
Former Cyborg Corps soldier Jasim Antar was relieved to come out of the war alive and looked forward to switching to a less violent line of work. But nobody wants to hire a brawny cyborg to do anything that doesn’t involve brutalizing people on a daily basis...

Categorized as:
galactic-empire military soldiers space-fleet space-opera war action-adventure adult
Wolf's Bane by Christopher G. Nuttall
Rated: 4.30 of 5 stars
· 10 ratings
The Commonwealth has won a great victory, smashing Wolfbane’s attempt to take Corinthian and driving Admiral Singh’s forces back into enemy space. Now, as the Wolves reel under the impact of their defeat - and powerful factions plot to take control of the government and military - Edward Stalker plans a final offensive to bring the Wolves to their knees...

Categorized as:
military soldiers space-fleet space-opera war action-adventure adult audiobook
Star Force: Origin Series by Aer-ki Jyr
Rated: 4.30 of 5 stars
· 10 ratings
The Origin Series is empire building at its finest, with 100 episodes and over 2.5 million words in the military science fiction serial detailing the rise of Star Force from corporate entity into an interstellar empire over the course of more than a millennium...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Star Force: Origin Series by Aer-ki Jyr
Rated: 4.30 of 5 stars
· 10 ratings
The Origin Series is empire building at its finest, with 100 episodes and over 2.5 million words in the military science fiction serial detailing the rise of Star Force from corporate entity into an interstellar empire over the course of more than a millennium...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel action-adventure adult
Reconnaissance in Force by Terry Mixon
Rated: 4.30 of 5 stars
· 10 ratings
When going to war, it pays to know your enemy. Particularly when they can crush you like a bug.Princess Kelsey Bandar has one slim chance to steal the tech her people needs to survive. Only a bold strike deep into enemy space keeps the New Terran Empire alive.Success gives them a chance. Failure dooms them to death and worse.Kelsey and her friends once again risk everything for their people...

Categorized as:
galactic-empire military soldiers space-fleet space-opera space-travel war action-adventure
Rich Man's War by Elliott Kay
Rated: 4.26 of 5 stars
· 30 ratings
Tanner Malone is starting to enjoy his navy post in the honor guard. After surviving violent conflicts with space pirates in the void, he hopes to stay out of the stars for a while. But when the government of Archangel, a prosperous Union state including four terraformed worlds, makes a dangerous decision to defy the Big Three’s corporate dominance, war threatens the galaxy...

Categorized as:
galactic-empire military soldiers space-fleet space-opera war action-adventure adult

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