The Imperial Civil War (Japanese: 銀河帝国内戦), also known as the Lippstadt War (Japanese: リップシュタット戦役), was a conflict fought in 797 UC (488 IC / 3597 CE) between the forces of the Lippstadt League (representing an Imperial establishment composed mainly of high nobles) and those commanded by Marquis Reinhard von Lohengramm.
In 796 UC (487 IC / 3596 CE), Kaiser Friedrich IV suffered a heart attack and died, having failed to assign a successor to his throne. The question of which of his three young grandchildren would ascend to the position led to a struggle amongst various parties who sought power within the Empire:
- Count Reinhard von Lohengramm, who initially had sought to overthrow Friedrich purely as a matter of justice or revenge (Friedrich had taken Reinhard's sister Annerose as a consort several years prior). His vision seemed later to have expanded, however, to include control over the entire Empire, and possibly all of Terran-controlled space. Lohengramm supported Erwin Josef II, the 5-year-old son of Princess Christine and the late Prince Ludwig. (LOGH: 'In the Eternal Night', 'Cool, Clear Artificial Eyes', 'New Trends')
- Marquis Klaus von Lichtenlade, who had served under Friedrich as his chief of staff and secretary of state. He too supported Erwin Josef, because the latter's lack of a strong parental influence would make the child easy to control.
- Duke Otto von Braunschweig, a high noble who had married the Kaiser's daughter Amarie. He supported his own child, 18-year-old Elisabeth, for obvious reasons.
- Marquis Wilhelm von Littenheim, another noble, who had married the Kaiser's other daughter Christine. He too supported his own daughter, 16-year-old Sabine.
After consulting with his advisers, Lohengramm chose to ally with Lichtenlade, as Lichtenlade lacked any military forces of his own, and together they were able to effect the ascension of Erwin Josef to the throne that same year. Coinciding with this event, the then-Count Lohengramm was given the title of Marquis.
Braunschweig, Littenheim, and other high nobles—outraged by Lohengramm's increased stature within the Empire, as well as their own reduction in power—forged an alliance of their own to fight the 'Lichtenlade-Lohengramm Axis'. The Lippstadt League was formally created at a gathering of nobles in the Lippstadt Forest on Duke Braunschweig's estates. Duke Braunschweig was the leader of the Lippstadt League with Marquis Littenheim as the 2nd in command.
Most of the high nobility sided with the Lippstadt League, either through pressure from family ties, feudal obligations, or simple inertia and desire to maintain the old status quo. One notable exception was the Mariendorf family which sided with Reinhard. (LOGH: 'New Trends', 'The Lippstadt Conspiracy')
Braunschweig had initially planned to station forces at 9 bases between Odin and Geiersburg Fortress, thinking the Lohengramm forces would exhaust themselves assaulting each base in series and stretch their supply lines. Merkatz opposed this dispersion of forces arguing the bases could be isolated and cut off. He instead proposed that the Lippstadt forces wholly retreat to Geiersburg to consolidate power in an impenetrable fortress. Admiral Staden tried to one-up Merkatz with adding an additional plan of sending a sortie against Odin to capture and then "protect" the infant Kaiser. However when chosen to implement this plan, Staden was defeated. Staden retreated to Rentenberg Fortress where Ovlesser commanded a force of Imperial armoured infantry. The Lippstadt fleet was defeated outside the fortress, but was pursued so closely upon their retreat that fortress guns could not fire for fear of hitting friendly ships. Despite some initial setbacks at the hands of Ovlesser, the fortress eventually fell to Reinhard's forces and Ovlesser was captured. He was released to return to Geiersburg Fortress, but as he was the sole prisoner released, Duke Braunschweig suspected (falsely) that Ovlesser was a traitor and had him killed, sowing the seeds of internal suspicion and doubt within the rest of the Lippstadt League. (LOGH: 'Bloodshed in Space')
The Lippstadt League's sole military success came during the brief period Merkatz was allowed free rein to fight as he chose, resulting in Merkatz forcing Admiral Oskar von Reuenthal into withdrawing from the Schann-tau system. However Merkatz's authority was undermined by the division of Lippstadt forces without his notification. Braunschweig had allowed Marquis Wilhelm von Littenheim to take a third of the Lippstadt forces ostensibly to regain control over rebellious frontier fiefs. The political rivalry between Braunschweig and Littenheim was longstanding and the ulterior motive of this was to get Littenheim away from Geiersberg Fortress. Littenheim would ultimately be defeated and Geiersburg Fortress itself would come under siege by Lohengramm forces. The final straw for Merkatz was when Braunschweig declined to punish insubordinate nobles that had sortied from the fortress without permission. Despite his loss of control as the Lippstadt military commander, Merkatz still rescued Braunschweig when the duke personally led an ill-advised offensive against the besieging Lohengramm forces that resulted in the Lippstadt League losing yet more of its ships. (LOGH: 'Courage and Loyalty')
The Westerland Massacre was a critical turning point in the Imperial Civil War. The planet Westerland was part of the territory held by Duke Braunschweig. In the aftermath of military setbacks, the Lippstadt League began heavier resource extraction from the territories under its control in order to prepare for an anticipated siege of their main base, Geiersburg Fortress. On Westerland, this resulted in the commoners rising up in revolt and Duke Braunschweig's nephew was killed in the ensuing struggle. (LOGH: 'The Fall of Goldenbaum')
Enraged by the death of his relative at the hands of commoners, Duke Braunschweig decided to make an example of the entire planet by launching nuclear missiles at it. The use of nuclear weapons on inhabited worlds had been a taboo since the Thirteen Day War. He overruled his aide, Commodore Ansbach, who had advocated a more selective policy of punishing only the ringleaders of the rebellion. (LOGH: 'The Fall of Goldenbaum')
When Duke Braunschweig launched a final desperate attack against the besieging Lohengramm forces, Merkatz participated despite knowing the attack was a poor tactical decision. The Lippstadt forces were dramatically weakened from poor morale and numerous desertions in the aftermath of the Westerland Massacre. When the Lohengramm forces counterattacked, a swift collapse of the Lippstadt forces ensued and Geiersburg Fortress fell due to internal insurrection. Cut off from returning to the fortress by Lohengramm forces, Merkatz initially planned to commit suicide as he would not serve under Marquis Lohengramm, having previously sworn loyalty to the Goldenbaum Dynasty. Merkatz was persuaded by his subordinate, Bernhard von Schneider, to seek refuge with Yang Wen-li in the Free Planets Alliance instead. (LOGH: 'The Fall of Goldenbaum')
The Imperial Civil War ended with the consolidation of the entire Empire's military forces under the control of Reinhard von Lohengramm. The Westerland Massacre resulted in widespread desertions from the Lippstadt League and shortened the duration of the war. This meant that the civil war was less damaging to the Empire's military than it otherwise might have been.
The defeat of the Lippstadt League broke the power of the high nobles both materially and politically. Their estates and assets were confiscated to replenish the Empire's treasury, and this wealth would fund Reinhard's later military expeditions. The Westerland Massacre had turned the public overwhelmingly against the nobles, dooming any attempts to restore the old status quo or the Goldenbaum Dynasty.