Karl Marx and Friedrich Engels were born within two years of each other, Marx 1818 in Trier and Engels in 1820 in Barmen (Wuppertal). While Marx received a formal education, obtaining a doctorate from the Friedrich Wilhelm IV University in Berlin, Engels was largely self-taught, since his father put him to work in the family business the moment he matriculated from the gymnasium at the age of seventeen. Although Marx was the deeper thinker of the two, Engels was by far the better writer. Both beat their own path to historical materialism, until their meeting of minds in Paris in 1844. From then on they were collaborators, settling finally in England to escape political persecution. From here they organized the International Working Mens Association, or First International, which quickly spread to other countries. Marx died from overwork at the age of sixty-five in 1883, while Engels lived on until 1895, eventually succumbing to throat cancer from his love of fine tobacco, wines and beer.

Since Marx and Engels made their living by writing, they wrote an immense amount of material. Much of it was journalism for various newspapers and magazines in Europe and North America, but a great deal also comprised substantial studies of economics, philosophy, history, politics, military matters and, last but not least, religion. The most complete collection of their works is the fifty-volume Marx and Engels Collected Works, published between 1975 and 2005.