Which Danish scientist is known as the originator of the three-age system of European antiquity?

Christian Jürgensen Thomsen (29 December 1788 – 21 May 1865) was a Danish antiquarian who developed early archaeological techniques and methods.

The three-age system is the periodization of history into time periods divisible by three; for example: the Stone Age, the Bronze Age, and the Iron Age;

In history, archaeology and physical anthropology, the three-age system is 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. It was 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.