Three-age system

The three-age system in history, archaeology and physical anthropology was a methodological concept adopted during the 19th century by which artifacts and events of late prehistory and early history could be ordered into a recognizable chronology. Initially developed by C. J. Thomsen, director of the Royal Museum of Nordic Antiquities, Copenhagen as a means to classify the museum’s collections according to whether the artifacts were made of stone, bronze or iron. The system first appealed to British researchers working in the science of ethnology and adopted it to establish race sequences for Britain's past based on cranial types. The craniological ethnology that formed its first scholarly context holds no more scientific value, the relative chronology of the Stone Age, the Bronze Age and the Iron Age is still in use in a general public context.

The structure reflects the cultural and historical background of Mediterranean Europe and the Middle East and soon underwent further subdivisions, including the 1865 partitioning of the age of stone into a Palaeolithic, Mesolithic and Neolithic by John Lubbock. It is, however of limited practicality for the establishment of chronological frameworks of Asian, Meso-American and other cultural spheres and occupies no importance in contemporary archaeological or anthropological research.

The concept of dividing pre-historical ages into systems based on metals extends far back in European history, probably originated by Lucretius in the first century BC, but the present archaeological system of the three main ages—stone, bronze and iron—originates with the Danish archaeologist Christian Jürgensen Thomsen (1788–1865), who placed the system on a more scientific basis by typological and chronological studies, at first, of tools and other artifacts present in the Museum of Northern Antiquities in Copenhagen (later the National Museum of Denmark). He later used artifacts and the excavation reports published or sent to him by Danish archaeologists who were doing controlled excavations. His position as curator of the museum gave him enough visibility to become highly influential on Danish archaeology. A well-known and well-liked figure, he explained his system in person to visitors at the museum, many of them professional archaeologists.

...
Wikipedia