Thomsen was the first to perceive typologies of grave goods, grave types, methods of burial, pottery and decorative motifs, and to assign these types to layers found in excavation. His published and personal advice to Danish archaeologists concerning the best methods of excavation produced immediate results that not only verified his system empirically but placed Denmark in the forefront of European archaeology for at least a generation. He became a national authority when C.C Rafn, secretary of the "Kongelige Nordiske Oldskriftselskab" ("Royal Society of Northern Antiquaries"), published his principal manuscript in "Ledetraad til Nordisk Oldkyndighed" ("Guide to Scandinavian Archaeology") in 1836. The system has since been expanded by further subdivision of each era, and refined through further archaeological and anthropological finds.