(Short note before we begin. Numbers of ships and people on all sides will be significantly increased, as Mass Effect's canon felt rather small scale in comparison to what Earth alone is capable of, let alone an entire galaxy.)
Edit: Changed a few details to match up with the next chapter and to better reflect the kind of scale I am trying for.
I: Command
'There's a sight to behold' Caelia Attius Aleria mused to herself as she gazed upon the newly completed Dreadnought that still sat in dry dock in the massive Imperial shipyards that lay in orbit in a massive ring above the planet Aedifex. The planet played host to the largest and most advanced ship production facilities in known space, utilizing the resources of the in-system gas giant and massive asteroid fields of the system to produce huge quantities of raw materials, fuel, and most importantly to her at the moment: Ships.
The Shipyards here were capable of producing hundreds of capital ships of all sizes in a single year while simultaneously turning out thousands of cargo vessels and corvettes, tens of thousands of fighters and shuttle craft, and tend to the maintenance of countless others. Of course that was assuming that enough crews and raw materials were available in constant supply. Most of the time it was running at barely a quarter of its potential at most, helping to meet the maintenance and refitting needs of the fleets both merchant and military along with producing any necessary replacement vessels along with the dozen or so equivalent installations that were spread throughout the core territories of the Terran Empire.
This shipyard had three years earlier been given the honor of designing and building the newest flagship of the legendary Emperor's own First Legion, officially known as Legio I Invicta, or Unconquered, which could trace its history back to the days of the Republic, and had a list of battle honors that filled entire volumes.
It was fitting that this Legion receive the first of the Germanicus class Dreadnoughts. The ships were the warships ever produced by the Empire, reaching more than 2.5 kilometers in length, and boasted some of the most powerful weapons and armor ever fielded. It was built around a central hull, split in two, with the slightly larger and wider upper section sitting slightly forward of the smaller lower section. The heavy angled armor of the two sections protecting the fighter and shuttle launch tubes and recovery bays, with the hull sections themselves housing the ship's main armament: three spinally mounted magnetic cannons each capable of launching a massive metal slug at near relativistic speeds. Build on either side of the ship and reaching about two thirds of the way up to the front of the hull were a set of downward facing delta wing-like structures that played host to four of the seven massive engines that would serve as the ship's primary propulsion, the other four being mounted in an inverse delta formation on the primary hull itself. The ship, while massive and imposing with its blocky angled hull and a silhouette that brought to mind a massive bird of prey in a dive actually presented a relatively small forward and broadside profile for a ship its size, while simultaneously capable of bringing nearly its entire armament to bear on any opponent.
Many early ship designers argued that a spheroid shape would be most efficient for a military vessel. However it was soon found in simulations that the sphere configuration did not use its armor with any degree of efficiency, with only the very edges of the ship's profile having enough angling in its armor to deflect incoming fire, and only being able to bring a portion of its weapons to bear at any given time, as such, the current theme of dagger shaped vessels was born and manifested beautifully in the ship that now waited patiently in its berth for the ceremonial launching of the ship after which it would embark on its shakedown cruise and join the fleet component of the First Legion.
The plan at this time assuming all went well, was that these ships would become the flagships of each legion's fleet element, replacing the aging Trajan class dreadnoughts that had served well for more than eighty years with numerous refits and upgrades along the way, but with the Imperial fleets moving to replace their mass effect cores with the new Mercury series drive cores as primary power sources and FTL drives along with advances in hull design and armor composition, they were becoming obsolete and would soon be relegated to the mothballed reserve fleets within the next year as the Germanicus' sister ships were put into mass production at ten different shipyards.
The sound of the door to the small observation room opening behind her and a familiar set of footsteps approaching pulled Caelia back to reality as Marcus Rutilius Macenna, her mentor of six years, and more notably Emperor of the Terran Empire and all her people, stood beside her in silence for a moment as he stopped to appreciate for the moment the scene before them. The man stood much taller than her, dwarfing her own shorter than average stature by more than a head at just over two meters. The Emperor had taken her under his wing six years ago after she had managed to not only become the youngest in centuries to be accepted into the Imperial Command School after managing to distinguish herself during her first years of mandatory military service at the age of eighteen, but also become the youngest ever to graduate the school and achieve the rank of Tribune commanding an entire cohort of the Comitatenses at the age of twenty, and a year later, leading her five thousand troops to successfully defeat an opposing force outnumbering her own more than five to one in that years simulated campaigns.
After the Emperor himself took notice of her unprecedented rise through the ranks and her display of tactical genius and strategic aptitude and decided to take her under his direct tutelage, intending to mold Caelia into a capable ruler, and in time and with a tremendous amount of work, his successor should she earn it.
This was one of the greatest reasons the Empire had survived as long as it had and one of the greatest differences that set the old Roman Empire apart from the reforged empire post Belisarius the Great's reforms. No longer was the position of Emperor a hereditary one. There were no more dynasties. Instead the Emperor would either pick the most capable candidate from among military commanders and regional governors to succeed him as had been the case with Marcus himself, or he would pick a promising young candidate and train them to become their successor should they prove themselves worthy, as was the case with Caelia. It was not a truly foolproof system, but there were failsafes in place to remove the occasional failure if necessary. The citizens would never again accept a corrupt, inept, or foolish Emperor.
"Take care of that ship, Caelia," Marcus stated in his typically straightforward manner, breaking the silence after a few moments. She turned sharply towards the much older man. He appeared to be in his latter middle ages, still strong, but beginning to age with lines showing on his face and his hair dark brown hair beginning gray. He appeared no older than fifty six, however human lifespan had increased dramatically over the course of the last thousand years of development, and Marcus himself was already two hundred and forty five, and could reasonably expect to remain active for decades to come. Similarly Caelia was, even in her much younger age of twenty seven already showing signs of this herself, appearing to be no older than twenty two.
"What do you mean?" She questioned, a slight edge of apprehension slipping into her voice as she already had an idea of what he meant.
Marcus simply gave a rare smile, allowing his normally tightly controlled expression to relax slightly before responding. "You know exactly what I mean. You have learned as much as you can from me, and it is time you take your first real command, step out from my shadow, and gain real experience in becoming protector and leader that you will need to be even hope to become my successor." The Emperor placed his hand on her shoulder before continuing, "It is time for you to start proving not just to me, but to the people, that you are capable of leading them."
Caelia's eyes widened before she simply nodded, not able to find her voice. She was making the next step on the road to the title of Princeps. She allowed him to draw back a step, and they then clasped arms as he used his free hand to replace the old clasp holding the purple cape signifying her status as ward of the Emperor in place over her shoulders with a new one in the shape of a golden eagle, announcing her as Legate of the First Legion before handing her a sturdy paper scroll, the hard copy of her new orders.
"Caelia Attius Aleria," he began, releasing her arm and straightening back up into a commanding posture, "You will take command of Legio I Invicta and her fleet components effective immediately and begin a ten year tour to supervise the exploration, fortification and settlement of the Nova Achaia sector. Your legion will proceed from here aboard the Germanicus to the Sol system to rendezvous with you legion, and proceed immediately to the Nova Achaia sector to begin your mission. Your objective is to see to the building of infrastructure and defenses on all suitable colony worlds, and to remain in control of this sector until the colonies are established and a sector government formed. After this is accomplished, you will remain in the sector to provide security until the tour is completed. Do you understand?"
Caelia stood tall, a determined glint in her eyes as she placed her right fist over her heart in salute. "Yes Imperator, it will be done." At his nod of acknowledgment she turned on her heel and marched from the room to her quarters to prepare.
Less than a half an hour later, Caelia stood at the head of the crew of the Germanicus alongside Admiral Kastanie Drescher, a veteran fleet officer in her early middle age who would command the Legion's fleet in its day to day operations; and Senior Tribune Alexios Komnenos, another experienced soldier in his prime who would do the same for the ground forces. The officers and crew had already known about her appointment to command of the legion, and simply nodded in acknowledgement as she had taken her place at the front of the formation of more than a thousand crewmen and a full cohort of five thousand heavily armed legionnaires with no great ceremony. This was expected however. In the Empire, ceremonies and special honors came only you accomplished something, and not a minute before.
The crew stood at rigid attention as the moment finally came, and the Germanicus was finally launched from drydock as the initial automated tests were run to ensure everything was in place before the crew came aboard. Suddenly the green light lit up above the door of the massive hangar bay, signalling that the ship was in perfect working order. Caelia, now Legate Aleria, performed an about face and preparing her carefully honed command voice as she prepared to give her first orders as Legate.
"Formation," her voice projected throughout the hangar in the absence of any other noise, "Fall out and board your vessel." She smiled as the soldiers began filing off in perfect columns of two rows each to board the large shuttles that would bring them to their home for the next ten years before sighing slightly and turning towards her command staff, who still waited for her command to board a smaller shuttle themselves.
"I'm going to be honest with you all," she began looking from face to face among her senior staff, "I have trained for years now to do this and more, but I am going to need your experience and skill to make this work. I hope I can count on your support?" They all nodded seriously as they sized up their new legate before Admiral Drescher spoke up.
"Of course, Legate"
"Good," Caelia replied, smiling slightly, "I look forward to working with you all. Now lets go before they decide to leave us behind." With a small round of chuckles they boarded their shuttle, and followed the crew out to their ship.
Caelia ran her hands through her hair as she sat at her desk in her small room aboard the Germanicus, leaning back from the computer terminal as she took a break from reading the many reports that came across her desk that day. It had been five years so far, and she and the First Legion had done well so far.
They had finished the infrastructure necessary for rapid and successful colonization on six different colony worlds so far, and had completed defensive fortresses and ground to orbit defense cannons on eight. These eight worlds were spread across the twenty five stars that had been designated to become a part of this sector to begin with while probes explored the stars further out from this Mass Relay for potential expansion of the sector in the decades to come as the sector core became more firmly established.
This was the general Imperial policy towards expansion in these days. Emperor Macenna had continued the policy of his forbear, which called for a steady but cautious expansion using the relay network as a sort of highway to new regions of space while expanding further and further from the relays themselves as the population in the new sector grew, especially with the new Mercury drive cores being brought into general use, allowing for travel farther and faster than ever before. This was checked though by ensuring that no new colonies of significant size were taken until a strong basic orbital defense network was complete, and military forces raised to protect the region. Already the Nova Achaia sector boasted a population in excess of two hundred million as settlers and retirees from the legions who had taken the option to have land granted to them in the new colonies moved in from all over Imperial space and while significant trade had yet to begin, Nova Achaia was poised to begin an economic boom within the next decade if all went well. As it stood, the First Legion was spread out among the colonies farther away from the Relay to bolster the garrisons of the colonies until the local Liminatei could be brought up to strength and more Comitatenses cohorts raised in order to defend the sector.
The modern Imperial military consisted of three major parts. First, there were the Liminatei, or the border guards. They consisted of varying numbers of lightly equipped and well trained infantry and a small local defense and anti piracy flotilla, along with orbital defense crewmen who consisted of conscripts who chose to serve their mandatory five years military service in their home planets' Liminatei rather than going the career military route and joining the Comitatenses, as well as being supplemented in times of emergency by veterans who had finished their service, but were still required to train with and maintain their basic equipment. These forces would form the first response to both military incursion and natural disaster, and serve as basic peacekeepers in their homes.
Second were the Comitatenses. These were cohorts of five thousand well trained and professional soldiers that formed the quick response forces of the Imperial military, using their exceptionally fast ships to deliver their troops to the threatened planet in a matter of hours to reinforce local forces and drive the threat off if possible, and when it was not. They would dig in deep to hold the line, making use of a vast array of defensive weaponry to hold the line both in space and on the ground until help can arrive.
Which leads to the third and most famous, though least numerous portion of the Imperial military machine. The Legions. The legions are the steel fist of the empire, comprised entirely of career soldiers drawn from the top two percent of all the troops available to the Empire. The modern legion consisted of fifty thousand ground troops and twenty five thousand ship crew and support staff totaling seventy five thousand souls. They recieved the best armor, weapons, and training available to the Empire and trained endlessly in order to be the very best at what they do. On the ground, the legions were highly mechanized, making use of main battle tanks, supporting artillery and air support and very disciplined mechanized infantry in infantry fighting vehicles to smash all that stand in their path. In space, Each legion fleet is centered around a massive dreadnaught ranging in size from two to two and a half kilometers long and escorted by five battlecruisers, two carriers, several cruisers and hundreds of destroyers and frigates protecting the multitude of transports carrying their ground forces into battle.
It was a good system, a great one even, that combined the legendary legions of the old empire with the lessons learned by the divided empires under siege, but it had not been tested in more than a millenia since the unification of Terra and while they trained diligently and prepared constantly, only time would tell if it was all worth it.
The young Legate was pulled out of her musings by an alert from her comms. "Go ahead," she commanded as she answered.
"Legate, the sector Consul sent an alert that the exploration flotilla send beyond Relay 314 has failed to check in. Nova Achaia has been placed on high alert, and the one hundred fifty seventh, three hundred thirteenth and four hundred and twentieth Comitatensis Cohorts are all scrambling to reinforce the colony in case of any possible attack."
That got her up and moving, putting her uniform back together with practiced efficiency as she dressed herself in her personal Lorica series armor set and began considering her own response. The exploration fleets did not miss a check in for any reason, it simply was not done, and in the event it was necessary, they would deploy a probe through the relay with a message explaining the situation before proceeding. For this to have happened meant something had happened, and while it was possible that it was nothing, she would not take that chance.
"Send the order to all of the legion to rendezvous on our position immediately, and send an alert to high command to the situation." She ordered as she fixed her last buckle, grabbed her helmet off the desk and placed her sidearm on her right thigh before rushing out the door and down the hall to the bridge.
"Yes Legate, the messages are sent and acknowledged." The communications officer reported just before the door opened and she entered the bridge. She considered her options while she waited for her officers to join her on comms. It would take several days to gather the First Legion, and likely at least a week before any real operations could begin on their end. It was worse if this became a major incursion, even through the Mass Relays as it takes a significant amount of time to prepare a single legion, let alone multiple legions, for a campaign of any length. More than likely, it would be a month before other legions could be brought to bear. She huffed in frustration. If there was an attack, the forces of Nova Achaia would just have to hold on their own until help could arrive.
So if you haven't already worked it out for yourself, Nova Achaia replaces Shanxi in this AU because while the Romans didn't really care about people's personal names so much, they tended to give places Roman or Latinized names, so calling it Shanxi just wouldn't make sense.
In the next chapter, we break out of pure exposition, the First Contact war begins and I get to finally write these actions scenes that I've had swimming in my head for a while.
As always, please let me know if I've messed something up or something doesn't make sense so that I can fix it. Thanks.