The "League of Communists" was a political organization founded in 1847 in Europe, primarily by Karl Marx and Friedrich Engels. It aimed to unite various communist groups and promote the ideas of communism, advocating for the working class's rights and the overthrow of capitalist systems. The League played a significant role in the development of communist theory, particularly through its publication of the "Communist Manifesto" in 1848. It later influenced various communist movements and parties, including those in Russia and Eastern Europe, contributing to the rise of communist states in the 20th century.