The Orionese War of Succession was a civil war and dynastic conflict over the succession to the Imperial throne of Orion, which lasted from 12 September 3005 to 20 January 3030. At the outset of the conflict, two competing noble houses claimed the succession to the throne after the death of the infirm and weak-willed Emperor John XIII of the House of Cauvan. The House of Cauvan perished at the Emperor's death, leaving the succession open to two cadet clans: the House of Gillemetz and the House of Lao. The throne was claimed by Margaret of Gillemetz and Henry, Duke of Lao, leading to open feudal warfare between the two and their immense private armies, joined by several divisions of mutineer Army troops. A third party, the House of Genevra, initially stayed out of the conflict and financed both sides, and maintained connections with the Terran Empire. After the House of Gillemetz was virtually destroyed, the House of Genevra inherited their claims through the marriage of the Gillemetz heiress Lenore to the Duke of Genevra. The Genevrists received immense Terran assistance and decisively defeated the Laoists in several battles in the late 3020s, especially after the neutral Orion Army sided with the House of Genevra. The conflict ended when the Laoist Emperor Paul I was killed in battle on 30 December 3029, and when Lenore and the Duke of Genevra were crowned on 20 January 3030. Lenore's co-emperor and husband, Emperor Martin, started the imperial House of Genevra.

The succession war was enormously costly, with around two million combatants killed in battle and over 600 million civilians killed. Over a billion civilians were injured or displaced due to the widespread destruction of the conflict. The reconstruction efforts were fraught with difficulty, but the donation of the entire ducal family fortune of the House of Genevra to the state treasuries effectively resolved the Empire's public debt. The empire took decades to fully recover.


The conflict is rooted in the dynastic complexities of the Orion empire, owing to the semi-feudal nature of the state at the time. The ruling dynasty, the House of Cauvan, had established themselves in 2769 after its inaugural ruler Henry Cauvan deposed his cousin John VIII of the House of Angevre. John was a widely unpopular ruler and had aroused the anger of the feudal dukes and the Army with various restrictions on their liberties and cuts to the Army's pay. He died childless, imprisoned after his deposition. Henry, Duke of Cauvan was crowned Henry III, ruling until his death in 2840.

The crown prince John Charles married his daughters into the important ducal houses to secure their loyalty; Maria into the House of Shands (which merged in-crown), Louise into the House of Gillemetz, and Julia to the House of Lao. He predeceased his father, so his eldest daughter Maria ascended the throne in 2929. She died in 2961 and was succeeded by her son John XII. He ruled until 2980 and was succeeded by his infant grandson John XIII.

Emperor John XIII is widely regarded as a weak ruler. He came to the throne in his infancy and his empire was ruled by a council of regents. He was continually under their strong influence, often to the detriment of the empire as the regents pursued their own power and self-gain. As he came of age, it was obvious that John XIII's reign was compromised by his unstable mental health; it is now known that he suffered from schizophrenia and epilepsy. Members of the regency council moved to have him declared an invalid and unfit to rule. The succession was the subject of heated discussion in the regency council and in Parliament. The Emperor had married his cousin Margaret of the House of Gillemetz, but had produced no children. On 3 January 3003, the Emperor died after a particularly severe epileptic fit. The regency council had yet to determine a successor, and competing claimants filed suit in civil court.

Empress Margaret claimed legitimacy from three ways: by jure uxoris and by descent from both Prince John Charles' third daughter Louise and from Maria I's second son Prince Febronius. She was prompted by her father Valens Gillemetz, 3rd Duke of Gille-de-Metz, to claim the throne.

Henry, 6th Prince Lao claimed legitimacy by descent from John XII's second daughter Julia and from John XII's second son and uncle to the recently-deceased king, Prince Martin. The court case dragged on for almost three years, until Margaret was declared Empress by the court on 30 August 3005.

The Interregnum saw an unprecedented increase in parliamentary power, and in the power of the landed aristocracy. With a breakdown in civil relations between the claimants, conflict was inevitable. However, this competition between the Houses of Lao and Gillemetz for the throne is largely seen as a pretext for the war. Many other factors contributed to the social upheaval and military anarchy of the period, including the increased independence and power of landed aristocrats, feuds between nobles and politicians, and the financial and human losses incurred by many noble families in the costly Orion-Soviet Wars.

Feudal warfare

Empress Margaret was declared Empress in late August, and sought to travel from her ancestral homeworld of Metz to the capital for a quick coronation. Prince Lao believed that not only would this put an end to his right to appeal the court's decision, but that he and his clan would be persecuted by the new Empress. He gathered an armed retinue of militarised spacecraft and intercepted the royal party when they stopped at the planet Albany for resupply. The skirmish was quick but saw the rout of the Gillemetz forces and the capture of Margaret's intended choice for Minister-President, Percy Lang, 9th Count of Langford. Lang was known as a fierce opponent of the House of Lao, and has been one of the leading members of the regency council. It was widely rumoured that he was the secret lover of Empress Margaret. Lao chose not to let him live, and had him blown out of an airlock without protective gear after verifying his identity.

Margaret, though uncrowned, considered herself the legitimate Empress and declared a state of emergency. She suspended the constitution, dissolved parliament, and issued an edict of attainder against Lao. The Prince Lao then issued a declaration acclaiming himself Emperor Henry IV and likewise issued a decree attainting 'Margaret of Gillemetz, false empress'. Open warfare broke out between the supporters of the two houses. Many lesser noble families, landed gentry, military leaders, and politicians sided with one or the other; some of them hoped to settle their own feuds with rivals, some aimed to 'ride the coattails' of the victorious party. The first phase of the conflict was mainly fought by these supporters as a proxy war, while the claimant royal houses fortified themselves on their homeworlds and gathered their retainers.

The military remained mostly neutral during this time. The professional head of the Imperial General Staff, Lord Admiral Edmund Wick, issued a statement of political neutrality and ordered all armed forces to stand down until the succession was settled by the feuding houses. That would change in 3011.


Admiral Wick died in April 3011. Both claimant houses appointed their leading supporters as head of the military and ordered units to mobilize. Margaret appointed Etienne Lang, 10th Count of Langford, the son of Percy Lang, as her chief minister and commander of the armed forces. Henry Lao appointed his chief general, Lance Yang as chief of the General Staff. The Orionese armed forces mutinied and split into competing factions, the enforced political neutrality having died with Admiral Wick. Open warfare thereafter consumed many worlds, and saw the deaths of millions of civilians. The feudal armies, bolstered by mutineers and mercenaries, engaged in vicious house-to-house fighting in thousands of major cities across the empire. Both sides sought a decisive battle of annihilation, but both were too cautious to do so and the conflict degenerated into a war of attrition. A troubling blow to the Lao cause came when General Yang defected to the Gillemetz side in 3015. But within a few years, the tide turned once again when Valens Gillemetz died in battle in 3019.

With their strongest leader dead, the Gillemetz party began to experience considerable difficulty and many nobles turned on each other. Internal disputes caused a breakdown in command, and they suffered a series of decisive defeats through 3020 and 3021. Many notable Gillemetz family members were killed in battle; when fortresses or manors were taken by force, women and children were not spared. The war of succession had by this point become a brutal, grueling war that all sides were exhausted by. None were in the mood for mercy. The capital fell in late 3020 to the Lao armies, and Henry was crowned on 4 January 3021. However, his son and heir Robert was killed in the battle and he was forced to declare his cousin Paul as his heir apparent.

In June of 3021, the Gillemetz homeworld of Metz was stormed by elite Orion Marines divisions loyal to the House of Lao in a surprise attack. Empress Margaret led the defence of the palace, but she was injured and disarmed. The planet was bombed, its cities looted and burned, and the population slaughtered. The Battle of Metz was the single bloodiest battle of the war, and saw 25 million civilian deaths. Margaret was taken to the capital, but refused to submit to Emperor Henry. He proposed that she marry him to bind their two houses and end the feud, but she again refused to submit. He televised her public execution by hanging, drawing, and quartering; it was an iconic moment of the war: the absolute barbarity of the conflict was in full view for the public. The act was condemned by the Terran Empire and other nations, who had previously remained neutral.

Emperor Henry engaged in a brutal suppression of the remaing Gillemetz loyalists, killing an estimated 100 million people in a systematic purge. As most of the Gillemetz loyalists had been of French and Irish descent, and Lao's party were mainly Mandarin, the killing has been described by some as an ethnically-motivated genocide. Other historians dispute this, focusing on the political and dynastic nature of the purge. The treacherous General Lance Yang, for instance, was publicly disembowelled.

Empress Margaret's sister, Princess Lenore, had inherited her claim as well as their father's dukedom. Lenore had secretly fled to the Terran Empire for her own safety. She secretly made a pact with her cousin, the Duke of Genevra, to initiate a rebellion in her favour.

Fall of the House of Lao

Henry IV acted swiftly to solidify his rule, but still faced considerable challenge. Army and Navy mutineers loyal to the Gillemetz cause turned to banditry and piracy as they were now targets of repression. They knew they would be tried for treason and mutiny, which would mean death sentences. Henry's short reign is largely remembered for its cruelty and brutality. Emperor Henry IV died in 3023, without surviving children or brothers. As decreed in 3021, he was succeeded by Prince Paul. As bloody as Henry's reign had been, Paul's was considerably more treacherous and paranoid in its cruelty. He saw treason everywhere, and executed even his close allies when he suspected them of plots against his throne. Even Army forces that had laid down their arms and pleadged fealty to Henry became unnerved and wary of the new Emperor. At the same time, Paul was eagerly searching for an empress so he could continue his dynasty but had no luck at courting one.

In 3025, empress-in-exile Lenore was secretly taken to Chanson, the fortified homeworld of Martin, 11th Duke of Genevra. In a televised media event, they were married in the ducal chapel and declared jointly to be Emperor and Empress regnant of the Orion Empire and challenged Prince Paul's claim to the throne. Mass revolts erupted across Orionese space, and over 150 divisions of the Army mutinied in their garrisons. The Terran Empire became involved in 3026 and dispatched supporting forces under the command of Admiral Anthony J. Acheron, ostensibly for peacekeeping and humanitarian reasons. While initially recognising Emperors Henry and Paul out of expedience, they revoked their recognition after the brutal purges and massacres became public knowledge. Paul and his supporters were forced to flee the capital in 3029 after three years of bitter fighting across the empire. The new Emperor and Empress led a fleet of capital ships to the fortress world of Bosworth in late December, where Paul had taken refuge. The battle raged in the planet's orbit, with Paul taking command at the front line. At the height of the battle, his previously-loyal supporters declined to commit their forces and several captains turned on him. His ship was obliterated by his former supporter Admiral Owen Nguyen, and he died in battle. The Genevrists under orders from Lenore committed to the orbital bombardment of Bosworth in retaliation for the destruction of Metz. A further 6 million civilians died in this last battle.

End and aftermath

A few skirmishes occurred in the following month, as retaliatory strikes by the few remaining Lao loyalists. But with no active claimant, support dried up swiftly. The Orion armed forces declared their fealty to the imperial couple. Martin and Lenore were crowned as co-emperors on 20 January 3030.

The couple declared the state of emergency over on 1 February, restoring the constitution, and called new elections for the imperial parliament to be held on 1 May. This effectively marked the end of the war, as Laoist revolt ceased after this point and the emperors resumed their constitutional role in concert with the elected government. Martin and Lenore had six children: John (b. 3031), Frederic (b. 3034), Margaret (b. 3036), Sarah (b. 3039), Percy (b. 3041), and Martin (b. 3044). Lenore died in childbirth in 3044, and Emperor Martin reigned alone until 3063 as the first ruler of the House of Genevra.

The Empire of Orion sufferred greatly in the conflict, with over half a billion civilian deaths. Several million soldiers died, and millions more were injured. All Orion military personnel were offered amnesty by Emperor Martin and were allowed their full pensions and benefits, which was a major factor in their siding with the Genevrists in the late 3020s. Over a billion civilians were injured or displaced by the widespread warfare.

The war saw indiscriminate bombings and attacks on civilian populations by both houses, as a way of weakening the resources of the other side in the conflict. At the same time, the conflict was also the height of the Orionese feudal system that had developed within the empire. The nobility of the Orion empire used the conflict as a way to settle old grudges and bad blood, leading to many nobles fighting at the front with their retainers or aboard spacecraft. As a result, over 40% of the Orionese nobles were killed in battle. Another 20% of the aristocracy were executed during the purges initiated by the Lao emperors. The Orionese nobility was largely replenished by "new men", upwardly-mobile gentry and professional functioanaries rewarded for their loyalty to the state in the aftermath of the war.

In the long term, the Empire of Orion came far closer to the Terran political orbit. The Terran Empire had provided considerable aid to place the House of Genevra on the throne and had sheltered empress Lenore during her exile. The Orionese royalty felt indebted to the Terrans, and the Terran government likewise expressed a feeling of being owed loyalty. The bond between the two nations, an their noble classes, strengthened. By the early 3100s, there was considerable overlap in their peerages and landholdings, which aided in the rise of the National Humanist party in the 3200s.

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