Karl Paul August Friedrich Liebknecht (; ; 13 August 1871 – 15 January 1919) was a German socialist politician and revolutionary. A leader of the far-left wing of the Social Democratic Party of Germany (SPD), Liebknecht was a co-founder of both the Spartacus League and Communist Party of Germany (KPD) along with Rosa Luxemburg.

Liebknecht was born in Leipzig as the son of SPD co-founder Wilhelm Liebknecht, and studied law and political economy. In 1907, he was imprisoned a year for writing an anti-militarism pamphlet, and in 1912 was elected to the Reichstag.

After the start of World War I, he vehemently opposed the SPD's support for the German war effort, co-founding the Spartacus League and beginning to call for revolution. Liebknecht was expelled from the party for his views in 1916, and again imprisoned for leading an anti-war demonstration. In 1917, the Spartacus League joined the Independent Social Democratic Party (USPD).

Liebknecht was released shortly before the November Revolution, during which he proclaimed Germany a "Free Socialist Republic" from the Berlin Palace on 9 November 1918. In December, his call to make Germany a soviet republic was rejected by the majority of the Reich Congress of Workers' and Soldiers' Councils, after which he became a founder of the KPD.

In January 1919, Liebknecht helped lead the failed Spartacist uprising against the SPD-ruled Weimar Republic, after which he and Luxemburg were captured and summarily executed by anti-communist Freikorps paramilitaries. Since their deaths, both Liebknecht and Luxemburg have become martyrs for the communist and socialist cause in Germany and throughout Europe. Commemoration of the two continues to play an important role among the German left to this day.

Life

Background Karl Paul August Friedrich Liebknecht was born in Leipzig in 1871, the second of the five sons of Wilhelm Liebknecht and his second wife Natalie (née Reh). His father, along with August Bebel, was one of the founders and key leaders of the SPD and its precursor parties. Karl was baptised a Lutheran in St. Thomas Church. According to the Liebknecht family tradition, their lineage was directly descended from the theologian and founder of Reformation, Martin Luther. His godparents included Karl Marx and Friedrich Engels, who were not present at the baptism but had written declarations of their godparenthood.

As a child in the early 1880s, Liebknecht lived in Borsdorf, now located on the eastern outskirts of Leipzig. His father had moved into a suburban villa there with August Bebel after they were expelled from Leipzig under the 'Lesser State of Siege', a provision of the Anti-Socialist Laws directed against socialist, social democratic and communist associations and writings. The laws were in force from 1878 to 1890.

Studies In 1890 he graduated from the in Leipzig and on 16 August 1890 began studying law and administrative cameral sciences at Leipzig University. He studied there with jurist Bernhard Windscheid, jurist and theologian Rudolph Sohm, economist Lujo Brentano, psychologist Wilhelm Wundt, and art historian Anton Springer. When the family moved to Berlin in October 1890, he continued his studies at the Friedrich Wilhelm University (now the Humboldt University of Berlin), where he attended lectures by historian Heinrich von Treitschke and economist Gustav Schmoller. His certificate of academic completion is dated 7 March 1893. On 29 May 1893, he passed his examination for higher civil service posts ().Wilhelm Liebknecht to Friedrich Engels on 9 June 1893.

Liebknecht then did his military service as a one-year volunteer with the Guard Pioneer Battalion, a unit of the Prussian Army, in Berlin in 1893 and 1894.

After a long search for a position, he wrote his doctoral thesis "Compensation Enforcement and Compensation Pleas According to Common Law" (), which was awarded a magna cum laude by the Law and Political Science Faculty of the Julius Maximilian University of Würzburg in 1897. On 5 April 1899 he passed the examination for candidates to the higher civil service career path with a "good".

Legal career

With his brother Theodor and the socialist and Zionist Oskar Cohn, he opened a law office in Berlin in 1899. In May of the following year he married Julia Paradies, with whom he had two sons, Wilhelm and Robert, and a daughter Vera.

He joined the Social Democratic Party (SPD) in 1900 and in 1904, along with his colleague Hugo Haase, he became known abroad as a political lawyer when he defended nine Social Democrats, among them the Pole Franciszek Trąbalski, in the Königsberg Secret Society trial. In other high profile criminal trials, he denounced the class-based justice of the empire and the brutal treatment of recruits in the military.

Treason trial

From 1907 to 1910 Liebknecht was president of the International Union of Socialist Youth, where he frequently spoke out against militarism. In 1907 he published Militarism and Anti-Militarism as part of the SPD Youth. In the work he argued that against an external enemy, external militarism required chauvinistic obstinacy, and against an internal enemy, internal militarism required a lack of understanding or hatred of any progressive movement. Militarism also needed an impassive people so that the masses could be driven like a herd of cattle. Anti-militarist agitation, he said, must educate about the dangers of militarism, but it must do so within the framework of the law – a statement that the Reich Court of Justice did not accept when Liebknecht was brought to trial for treason. He characterized the spirit of militarism with a reference to a remark by the Prussian Minister of War at the time, General Karl von Einem, according to whom a soldier loyal to the king who shoots badly is preferable to one who shoots well but whose political convictions are questionable. On 17 April 1907 von Einem asked the Reich Prosecutor's Office to initiate criminal proceedings against Liebknecht on account of the pamphlet.

The treason trial against Liebknecht took place before the Reich Court of Justice, presided over by Judge Ludwig Treplin, on 9, 10 and 12 October 1907, with a large public presence. On the first day of the trial, Liebknecht said that imperial orders were null and void if their purpose was a breach of the constitution. (In the court's final ruling, it emphasized that the soldiers' unconditional duty of obedience to the emperor was a central provision of the constitution of the empire.) When Liebknecht responded to a question from the presiding judge by saying that various newspapers as well as the conservative politician Elard von Oldenburg-Januschau were calling for a violent breach of the constitution, the judge cut him off, saying that he could allege that statements had been made in his courtroom that he had understood to be an incitement to a breach of the constitution. On the third day of the trial, Liebknecht was sentenced to one and a half years imprisonment () for acts preliminary to high treason.

Emperor Wilhelm II, who had a copy of Militarism and Anti-Militarism, was informed about the Liebknecht trial several times by telegraph. He received a detailed report after the verdict was pronounced, but Liebknecht was not sent a copy of the written verdict until 7 November. His self-defense at the trial brought him considerable popularity among Berlin's workers, and a throng of people escorted him to prison.

Member of the Prussian Parliament and the Reichstag

In 1908 Liebknecht became a member of the Prussian House of Representatives even though he had not yet been released from prison in Silesia. He was one of the first eight Social Democrats to become a member of the Prussian state parliament, despite the Prussian three-class franchise that gave more weight to higher-income voters. Liebknecht remained a member of the state parliament until 1916.

His wife Julia died on 22 August 1911 after a gall bladder operation. Liebknecht married Sophie Ryss (1884–1964) in October 1912.

Following the national election of January 1912, Liebknecht, who was just 40, entered the Reichstag as one of the youngest SPD deputies. After unsuccessful attempts in 1903 and 1907, he won the "imperial constituency" of Potsdam-Spandau-Osthavelland, which until then had been the safe domain of the German Conservative Party. In the Reichstag he immediately emerged as a staunch opponent of an army bill that would grant the emperor tax funds for armaments for the army and navy. He was also able to prove that the Krupp company, a large steel and armaments firm, had illegally obtained economically important information by bribing employees of the War Ministry (the so-called Kornwalzer scandal).

First World War

In the first half of July 1914 Liebknecht traveled to Belgium and France, where he met with socialist politicians Jean Longuet and Jean Jaurès and spoke at several events. He spent the French national holiday in Paris. He only became aware of the danger of a European war on 23 July, after the Austro-Hungarian ultimatum to Serbia became known (the July Crisis). At the end of July, he returned to Germany via Switzerland.

On 1 August, the day mobilization was announced and war declared on Russia, the Reichstag was summoned for a 4 August session. At the time there was still no question in Liebknecht's mind that "the rejection of war loans was self-evident and unquestionable for the majority of the SPD Reichstag faction". In the party's preparatory meeting on 3 August, there were, according to SPD representative Wolfgang Heine, "vile, noisy scenes" because Liebknecht and 13 other deputies spoke out decisively against war loans. In the 4 August parliamentary session, however, the Social Democratic faction voted unanimously in favor of approving the loans that enabled the government to finance the initial war effort.

Before the parliamentary group meeting on 3 August, those in favor of the approval had not expected such a success and had been by no means sure of even obtaining a majority in the SPD parliamentary group. Even during the break in the session after Reich Chancellor Theobald von Bethmann Hollweg's speech, immediately before the vote, there was turmoil among the SPD deputies because some had demonstratively applauded the Chancellor's remarks. Liebknecht, who in the years before had repeatedly defended the unwritten rules of party discipline (i.e. unanimity) against representatives of the party's right wing, bowed to the decision of the majority and also voted for the government bill in the Reichstag's full session. Hugo Haase, who like Liebknecht had opposed the loan in the parliamentary group, agreed for similar reasons to read the statement of the parliamentary group majority, which was received with jubilation by the bourgeois parties. Liebknecht often thought about or discussed the events of 4 August, both privately and in public. He saw them as a catastrophic political and personal watershed. In 1916, he noted:"The defection of the majority of the parliamentary group came as a surprise even to the pessimists; the atomization of the hitherto predominant radical wing no less so. The importance of the credit approval in the shift of the faction's entire policy to the government camp was not obvious: there was still the hope that the decision of 3 August was the result of a temporary panic and would soon be corrected, or at least not repeated and even overridden. These and similar considerations, but also uncertainty and weakness, explained the failure of the attempt to win over the minority for a separate public vote. But what must not be overlooked is the sacred veneration that was still paid to party discipline at that time, and most of all by the radical wing that until then had had to defend itself ever more pointedly against breaches of discipline, or tendencies to break discipline, on the part of revisionist party members."