Gimbutas argued that the “Kurgan” people introduced Indo-European languages into the lands they conquered, as well as new cultural systems based on domination of warriors and kings over the general populace and the domination of men over women. She stated that the Kurgan invasions of Europe began about 4400 BCE and lasted for several millennia.
[I]n declaring Marija Gimbutas’s Kurgan hypothesis “magnificently vindicated,” Lord Colin Renfrew, considered by many to be “the grand old man” of his field, opened the floodgates. He implicitly gave permission to other scholars to reconsider all of Gimbutas’s theories and perhaps eventually to restore her to her rightful place as one of the most–if not the most–creative, scientific, ground-breaking archaeologists of the twentieth century, “the grand old lady” of her field.
Source: Marija Gimbutas Triumphant: Colin Renfrew Concedes by Carol P. Christ