The German Empire is the common name given to the state designating Germany from its unification in 1870 to 2501, when it became forcefully assimilated to the American Empire and later the Coalition of Western Republics.
Germany was unified around Prussia by 1870, following a series of wars, including with its neighbor France.
In 1916, Germany entered the Kaiser's War on the side of the Allies after it was attacked by France in fear of a possible German invasion, which was the result the various alliance systems put in place across Europe. Following several years of stalemate, Germany defeated Austria, Britain and France. It thus established itself as the unofficial hegemon of central Europe.
Hostilities in Europe resume when Germany reacted to increasing unrest in the former Austro-Hungarian Empire. A violent German intervention further provoked Britain and France to establish a blockade on Germany and eventually declaring an unrestricted submarine warfare against any vessels inbound for Germany. This action infuriated Germany and its trading the United States, which the former inclined in defending their trade. Eventually the former Entente powers declared war on Germany in January 5, 1941.
Germany stopped Entente forces at the Rhine River and subsequently pushing back the Entente at the Battle of Hamburg. Afterward, Germany regains its territories earlier lost to the Entente before advancing into France. By June 1944, German forces captured Paris and forcing France into a unconditional surrender. Germany later, reluctantly, established a temporary alliance with the Soviet Union against the Ottoman Empire and ending in that nation's defeat to the Soviets. As the global conflict ended, Germany arise as one of the three great powers alongside the United States and the Soviet Union.
After the Collapse, the German and American governments had trouble coordinating resources to colonize and rebuild in the Columbia System. Out of necessity and survival, the German and American governments effectively united. Although both governments competed with one another, causing mistrust and national rivalry. However, the leaders of the two empires remained committed to alliance in the face of trying times, knowing that war between the two would result in mutual destruction. This alliance culminated in the arranged marriage between Nicholas Jackson, son of American emperor Steven II and Princess Anne of the German Empire, in 2311. The two empires were united in personal union under their son, Nicholas II, but the two governments were technically separate.
Nicholas II attempt to balanced the interests of his German and American subordinates so neither would feel marginalized. Unfortunately, American influence dominate the Imperial government to the point that the Germans were effectively an ethnic minority in an American state. Nicholas II try to resolve this imbalance by seizing more power from Congress and the Reichstag, which consequently causing massive opposition from both organizations and their temporarily dismantlement in the "Columbia Captivity". This met with violent response from the Germans, referred to as "Kaiserites", which they purged their star systems from Imperialist forces and the German aristocracy crowning Gustav II, King of Prussia, as their new Kaiser in 2383. The coronation was interrupted by Imperial authorities, sparking the Endless War.
Despite Nicholas II's attempt to negotiate with the Kaiserites, the Germans refused to negotiate until the Reichstag, but not Congress, was released from captivity. After Nicholas II end the Columbia Captivity and removing Imperial forces from the Breslau system, the Germans further demanded for the emperor's abdication, full removal of the German Empire from any union with the United States and 50% of all government resources. Nicholas II refused the demands in which the Kaiserites declared the reformation of the German Empire. The Kaiserites became a reckoning force and were able to conquer many star systems until the tide of war turned against them at the hands of American forces, whom Nicholas II conceded to. By the turn of the 25th century, the Kaiserite stronghold of Wittenau was taken by Imperial forces and the German aristocracy was destroyed almost completely. Only very few Kaiserite forces managed to escaped from Imperial custody and would last until their surrender to the Coalition of Western Republics in 2501.
In spite the disintegration of the German Empire, only a few surviving German-based enclaves that claimed themselves as successors to the German Empire exists. Particularly the Empire of Ostland and those in the Platte System.