Socialists of 19th century Europe:
- Karl Marx: Karl Marx was a German philosopher, economist, and political theorist. He is best known for his work in developing the theory of communism and socialism. Marx co-authored "The Communist Manifesto" with Friedrich Engels, which outlines their vision for a classless society.
- Friedrich Engels: Friedrich Engels was a German philosopher, social scientist, and communist revolutionary. He collaborated closely with Karl Marx and co-authored "The Communist Manifesto" with him. Engels played a significant role in developing Marxist theory.
Other important socialists of 19th century Europe include:
- Robert Owen: Robert Owen was a Welsh social reformer and industrialist. He advocated for workers' rights, including the idea of cooperative communities where workers would share in the profits and decision-making.
- Pierre-Joseph Proudhon: Pierre-Joseph Proudhon was a French politician, economist, and philosopher. He is considered one of the early proponents of anarchism and mutualism, advocating for a system where workers would own and control the means of production.
- Ferdinand Lassalle: Ferdinand Lassalle was a German socialist and labor leader. He played a crucial role in the formation of the first German workers' party, the General German Workers' Association, which later became the Social Democratic Party of Germany.
- August Bebel: August Bebel was a German socialist politician and co-founder of the Social Democratic Party of Germany. He advocated for workers' rights, women's suffrage, and social welfare reforms.
These are just a few examples of important socialists in 19th century Europe. They played significant roles in shaping socialist theory and the labor movement during this period.

Karl Marx and Friedrich Engels were important socialists of 19th century Europe. They played a significant role in shaping socialist ideology and their works had a profound impact on political and economic thought during that time.

1. Karl Marx:
- Marx was a German philosopher, economist, and sociologist. He is best known for his works on communism and socialism, particularly "The Communist Manifesto" and "Das Kapital."
- Marx believed that capitalism was inherently exploitative and that it would eventually lead to its own downfall. He argued that the working class, or the proletariat, would rise up against the bourgeoisie, the capitalist class, in a revolution.
- Marx's theory of historical materialism emphasized the importance of economic factors in shaping society. He believed that class struggle was the driving force behind historical change.

2. Friedrich Engels:
- Engels was a German philosopher, social scientist, and political theorist. He collaborated closely with Marx and co-authored several works with him.
- Engels played a crucial role in developing and popularizing Marxist theory. He helped Marx refine his ideas and provided financial support to him.
- Engels' most notable work is "The Condition of the Working Class in England," in which he exposed the harsh living and working conditions of the proletariat during the Industrial Revolution.

Importance of Marx and Engels:
- Marx and Engels' writings had a profound influence on socialist and communist movements across Europe. Their ideas formed the basis for the establishment of socialist parties and the development of labor unions.
- Their critique of capitalism and advocacy for workers' rights and equality resonated with many who were dissatisfied with the social and economic conditions of the time.
- Marx and Engels' works continue to be studied and debated by scholars and activists today. Their ideas have had a lasting impact on political and economic thought, and their writings remain foundational texts for understanding socialism and communism.