Increasingly the Iron Age in Europe is being seen as a part of the Bronze Age collapse in the ancient Near East, in ancient India (with the post-Rigvedic Vedic civilization), ancient Iran, and ancient Greece (with the Greek Dark Ages). In other regions of Europe the Iron Age began in the 8th century BC in Central Europe and the 6th century BC in Northern Europe. The Near Eastern Iron Age is divided into two subsections, Iron I and Iron II. Iron I (1200–1000 BC) illustrates both continuity and discontinuity with the previous Late Bronze Age. There is no definitive cultural break between the 13th and 12th centuries BC throughout the entire region, although certain new features in the hill country, Transjordan and coastal region may suggest the appearance of the Aramaean and Sea People groups. There is evidence, however, of strong continuity with Bronze Age culture, although as one moves later into Iron I the culture begins to diverge more significantly from that of the late 2nd millennium.
The Iron Age as an archaeological period is roughly defined as that part of the prehistory of a culture or region during which ferrous metallurgy was the dominant technology of metalworking. The periodization is not strictly tied to the presence of ferrous metallurgy and is to some extent a matter of convention.
The characteristic of an Iron Age culture is mass production of tools and weapons made from steel, typically alloys with a carbon content between approximately 0.30% and 1.2% by weight. Only with the capability of the production of carbon steel does ferrous metallurgy result in tools or weapons that are equal or superior to bronze. To this day bronze and brass have not been replaced in many applications, with the spread of steel being based as much on economics as on metallurical advancements. A range of techniques have been used to produce steel from smelted iron, including techniques such as case-hardening and forge welding that were used to make cutting edges stronger.
By convention, the Iron Age in the Ancient Near East is taken to last from c. 1200 BC (the Bronze Age collapse) to c. 550 BC (or 539 BC), taken as the beginning of historiography (Herodotus) or the end of 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 "Iron Age" for various regions of the Old World, with indication of the subsequent historical epoch.