Historical materialism which is an analysis of history through the lense of dialectical materialism which is the philosophical and scientific basis for Marxism. Essentially viewing history as a continuous development of the means of production motivated by societal contradictions. The focus is specifically on conflict that arises between the owning classes and the laboring classes of each historical mode of production.
I just smoked so this may not be the best explanation but its the best I got in me rn