Did Karl Marx believe that the key to human history was class struggle?

Yes, Karl Marx believed that class struggle is the fundamental driving force of human history. He argued that societal development is primarily shaped by the conflicts between different social classes, particularly between the bourgeoisie (capitalist class) and the proletariat (working class). According to Marx, these struggles lead to social change and the evolution of economic systems, ultimately culminating in the establishment of a classless society.