Oscar Montelius
Oscar Montelius (9 September, 1843 - 4 November, 1921) was a Swedish archaeologist who took the three-age system originally devised by Christian Jürgensen Thomsen in Denmark and sub-divided it further. He divided the Neolithic into four numbered periods, I-IV, and the Bronze Age into three more I-III.By taking calendrical dates from the recently deciphered hieroglyphics of Ancient Egypt, Montelius employed a complex system of cross-dating through typologies and associated finds to apply firm dates to archaeological finds and features all over Europe.
His diffusionist theories were eventually displaced by more complex views of cultural interaction but following refinement his system of sub-divisions is still effectively in use.