Hugo Eberlein was born in 1887. As a young man he joined the Social Democratic Party (SDP). Eberlein was a leading figure in the anti-militarist section of the SDP.
Karl Liebknecht was the only member of the Reichstag who voted against Germany's participation in the First World War. He argued: "This war, which none of the peoples involved desired, was not started for the benefit of the German or of any other people. It is an Imperialist war, a war for capitalist domination of the world markets and for the political domination of the important countries in the interest of industrial and financial capitalism. Arising out of the armament race, it is a preventative war provoked by the German and Austrian war parties in the obscurity of semi-absolutism and of secret diplomacy." Immediately after the vote on war credits in the Reichstag, a group of SDP anti-militarist activists, including Eberlein, Ernest Meyer, Franz Mehring, Wilhelm Pieck, Julian Marchlewski and Hermann Duncker met at the home of Rosa Luxemburg to discuss future action. They agreed to campaign against the war but decided against forming a new party and agreed to continue working within the SPD.
Over the next few months members of this group were arrested and spent several short spells in prison. On the release of Luxemburg in February 1916, it was decided to establish an underground political organization called Spartakusbund (Spartacus League). The Spartacus League publicized its views in its illegal newspaper, Spartacus Letters. Like the Bolsheviks in Russia, they began to argue that socialists should turn this nationalist conflict into a revolutionary war.
Dick Howard has argued: "Agitation continued throughout the war; yet the Spartacus League was never very strong. All agitation had to be carried out in strict secrecy, and the leaders were more often than not in jail." Members included Duncker, Rosa Luxemburg, Karl Liebknecht, Leo Jogiches, Paul Levi, Ernest Meyer, Franz Mehring, Clara Zetkin, Wilhelm Pieck, Julian Marchlewski and Hermann Duncker.
On 1st May, 1916, the Spartacus League decided to come out into the open and organized a demonstration against the First World War in the Potsdamer Platz in Berlin. One of those who attended reported: "It was a great success. At eight o'clock in the morning a dense throng of workers - almost ten thousand - assembled in the square, which the police had already occupied well ahead of time. Karl Liebknecht, in uniform, and Rosa Luxemburg were in the midst of the demonstrators and greeted with cheers from all sides." Several of its leaders, including Karl Liebknecht and Rosa Luxemburg were arrested and imprisoned.
Karl Radek, a member of the Bolshevik Central Committee, argued that the the Soviet government should help the spread of world revolution. In 1918 he was sent to Germany and with a group of radicals, including Rosa Luxemburg, Karl Liebknecht, Leo Jogiches, Paul Levi, Wilhelm Pieck, Julian Marchlewski, Hermann Duncker, Paul Frölich, Ernest Meyer, Franz Mehring and Clara Zetkin, helped to establish the German Communist Party (KPD).
In Germany elections were held for a Constituent Assembly to write a new constitution for the new Germany. As a believer in democracy, Rosa Luxemburg assumed that her party would contest these universal, democratic elections. However, other members were being influenced by the fact that Lenin had dispersed by force of arms a democratically elected Constituent Assembly in Russia. Luxemburg rejected this approach and wrote in the party newspaper: "The Spartacus League will never take over governmental power in any other way than through the clear, unambiguous will of the great majority of the proletarian masses in all Germany, never except by virtue of their conscious assent to the views, aims, and fighting methods of the Spartacus League."
On 1st January, 1919, at a convention of the Spartacus League, Luxemburg was outvoted on this issue. As Bertram D. Wolfe has pointed out: "In vain did she (Luxemburg) try to convince them that to oppose both the Councils and the Constituent Assembly with their tiny forces was madness and a breaking of their democratic faith. They voted to try to take power in the streets, that is by armed uprising. Almost alone in her party, Rosa Luxemburg decided with a heavy heart to lend her energy and her name to their effort."
In January, 1919, Karl Liebknecht, Rosa Luxemburg, Leo Jogiches and Clara Zetkin organised the Spartakist Rising that took place in Berlin. Friedrich Ebert, the leader of the Social Democrat Party and Germany's new chancellor, called in the German Army and the Freikorps to bring an end to the rebellion. By 13th January the rebellion had been crushed and most of its leaders, including Liebknecht and Luxemburg. They were both murdered while in police custody. Eberlein was arrested but was eventually released. In 1921 he was elected to the Reichstag.
After Adolf Hitler gained power in 1933, Eberlein fled to the Soviet Union. As a former supporter of Rosa Luxemburg he was treated as an unreliable communist by Joseph Stalin. In January 1938, was interrogated and tortured for ten days and nights. He was eventually sent to Lefortovo Prison and in 1939, he was sentenced to 15 years in the Vorkuta Gulag. He was returned to Moscow in 1941, when he was tried and sentenced again and was shot on 16th October, 1941.