From Wikipedia

Ancient Worlds - Age of Iron

In archaeology, the Iron Age is the period in any area during which cutting tools and weapons were mainly made of iron or steel. The adoption of this material coincided with other changes in society, including differing agricultural practices, religious beliefs and artistic styles.

The Iron Age is the last principal period in the three-age system for classifying ancient societies, preceded by the Bronze Age and the Stone Age. Its dates and context vary depending on the geographical region. The Iron Age in each area ends with the beginning of the historical period, i.e. the local production of ample written sources. Thus, for instance, the British Iron Age ends with the Roman Conquest.