Nordic Bronze Age objects. These valuable metals were all imported, primarily from Central Europe, but they were often crafted locally and the craftsmanship and metallurgy of the Nordic Bronze Age was of a high standard. The archaeological legacy also comprise locally of crafted wool and wooden objects and there are many tumuli and rock carving sites from this period, but no written language existed in the Nordic countries during the Bronze Age. The rock carvings have been dated through comparison with depicted artifacts, for example bronze axes and swords. There are also numerous Nordic Stone Age rock carvings, those of northern Scandinavia mostly
Iron Age the proto-historical period. In Central and Western Europe, the Iron Age is taken to last from c. 800 BC to c. 1 BC, in Northern Europe from c. 500 BC to 800 AD. In China, there is no recognizable prehistoric period characterized by ironworking, as Bronze Age China transitions almost directly into the Qin dynasty of imperial China; "Iron Age" in the context of China is sometimes used for the transitonal period of c. 500 BC to 100 BC during which ferrous metallurgy was present even if not dominant. The following gives an overview over the different conventions delimiting the