He is best remembered as the initiator of the country's social-democratic movement, which after his death led to the formation of the Social Democratic Party of Germany (SPD) in 1875.

His father Heyman Lassal was a Jewish silk merchant and intended his son for a business career, sending him to the commercial school at Leipzig.

[2] There, Lassalle met the poet Heinrich Heine, who wrote of his intense young friend in 1846: "I have found in no one so much passion and clearness of intellect united in action.

[3] Back in Berlin to work on his book, Lassalle met Countess Sophie von Hatzfeldt, a woman in her early 40s who had been separated from her husband of many years and who had an ongoing dispute with him regarding the disposition of the couple's property.

During the German Revolutions of 1848, he spoke at public meetings in favor of the revolutionary-democratic cause and urged the citizens of Düsseldorf to prepare themselves for armed resistance in advance of the violence that was expected after the decision of the Prussian government to dissolve the National Assembly.

[9] Banned from residence in Berlin in the aftermath of his conviction, Lassalle moved to the Rhineland, where he continued to pursue the lawsuit of the Countess von Hatzfeldt (settled in 1854) and finished his work on the philosophy of Heraclitus, (completed in 1857 and published in two volumes the following year).

[10] Reaction to the book was mixed as some declared the work seminal while others, including Karl Marx, considered it a mere recitation of Hegelian axioms.

He left his legal practice and philosophy in favor of drama, authoring a play called Franz von Sickingen, a Historical Tragedy.

[12] The work was characterized by Eduard Bernstein, an early and sympathetic biographer, as awkward and prone to excessive oratory, unsuited for the stage despite several effective scenes.

[13] Lassalle appealed to his friend, the aging scholar Alexander von Humboldt, to intercede on his behalf before the king to rescind the ban and allow his return.

[14] As a recognized legal scholar, Lassalle was asked to make public addresses dealing with the nature of the constitution and its relationship to the social forces within society.

[17] In another speech, delivered in Berlin on 12 April 1862, later known as the Workers' Program, Lassalle assigned moral primacy in society to the working class over the bourgeosie, an assertion regarded as dangerous by the Prussian censorship.

[19] On 22 October 1862, a few worker delegates who had visited London had come back with left-wing ideas, and published an open letter about the political and economic situation of the working class.

[21] Lassalle soon began a new career as a political agitator, traveling around Germany, giving speeches and writing pamphlets in an attempt to organise and rouse the working class.

In 1864, Lassalle made several secret appeals to Bismarck, later the main proponent of the Anti-Socialist Laws, in favor of the immediate implementation of progressive policies such as universal suffrage.

[22] Lassalle attempted to make common cause with the conservative Bismarck in his book Herr Basitat-Schulze, declaring that he "must inform Your Excellency that this work will bring about the utter destruction of Liberals and the whole Progressive bourgeoisie.

[23] The book subsequently appeared without police interference, but Bismarck, occupied with other matters, refused a request by Lassalle for another meeting and no further direct contacts between the pair were made.

[24] Élie Halévy would later write on this situation:Lassalle was the first man in Germany, the first in Europe, who succeeded in organising a party of socialist action.

His whole character is that of an epicurean god, unwittingly become man, awakening suddenly to the existence of evil, and finding with amazement that his will is not omnipotent to set it right.

[30] In Rigi Kaltbad, Lassalle met a young woman named Helene von Dönniges and during the summer of 1864 they decided to marry.

Apparently under duress, she soon renounced Lassalle in favour of another suitor, a Wallachian prince named Iancu Racoviță, to whom she had previously been betrothed.

It is all sentiment, and whether he refers to the cause he represented or to himself, he never speaks to the jury, but to the gallery, to an imaginary mass meeting, and after declaring a vengeance that should be "as tremendous" as "the insult offered the people," he ended with a recitation from Schiller’s Tell.Also on theoretical and political matters, their opinions diverged.

Indeed, Marx's essay Critique of the Gotha Program is written in part as a reaction to Lassalle's ideas within the socialist party of Germany.

[39] In September 1878, Bismarck was pressed by Social Democratic representative August Bebel in the Reichstag to provide details about his past relationship with Lassalle, prompting the Chancellor to make the following statement: I saw him, and since my first conversation I have never regretted doing so.

As I have said he was ambitious, on a large scale, and there is perhaps room for doubt as to whether, in his eyes, the German Empire ultimately entailed the Hohenzollern or the Lassalle dynasty.

[41] Owing to his premature death by a duel at age 39, just two years after his serious entry into German radical politics, Lassalle's actual contributions to socialist theory are modest.

[42]In contrast with Marx and his adherents, Lassalle rejected the idea that the state was a class-based power structure with the function of preserving existing class relations and destined to wither away in a future classless society.

[43] Lassalle accepted the idea first posited by the classical economist David Ricardo that wage rates in the long term tended towards the minimum level necessary to sustain the life of the worker and to provide for his reproduction.

"[45] Lassalle defended a homosexual member of his party, Johann Baptista von Schweitzer, who was attacked[clarification needed] merely because of his sexual orientation.

Lassalle on the other hand defended Schweitzer against such attacks:[46] Such behavior against a man of your character and your intelligence only proves how confused and narrow-minded the political ideas of our people still are.