I have recently been involved in an interesting discussion Elsewhere on the subject of Cultural Marxism and the Frankfurt School. Simplistically, Political Marxism morphed into Cultural Marxism from there to Political Correctness and Multiculturalism. Thus Marxism is responsible for all the ills of the Western World today.
But that is just the background. I have made mention on this site that I studied history, and I was intrigued by the views of Marxist Historians. Very simply, it was a way of looking at historical events which gave more importance to underlying socio-economic factors.