What was the Iron Age?
The Iron Age is defined by the process of taking rocks that contain iron (iron ore), heating them to temperatures over 1,000 degrees Celsius to help remove impurities (smelting), then hammering the iron into finished products: the production of wrought iron.
[Here is a nice link describing the process in detail]
When did the Iron Age begin?
The earliest examples of Iron Age technology are from the areas around modern Turkey, Iraq, Iran, Israel and Egypt and date to approximately 1,200 BC.
When did the British Iron Age begin?
It took centuries for the technologies of the Iron Age to reach Britain and the changes from the earlier Bronze Age were gradual. But 800 - 700 BC. is a widely used starting figure. The Iron Age ends in Britain with the Roman conquest in 43 AD, so a reasonable dating for the British Iron Age is 800 BC – 43 AD. Bronze continues in use through the Iron Age.
Hillforts
Hillforts appear in Britain from around the beginning of the Iron Age. Hillforts like Maiden Castle are in commanding positions and well defended by earthwork banks. But not all hillforts are like this. The sites we call hillforts vary a lot from place to place. They appear to have had many purposes, including the enclosing of settlements, animals and the storage of grain but they do all seem to start appearing with the beginning of the Iron Age, before declining in the later Iron Age, around 100 BC.
Who were the people of the British Iron Age?
The school curriculum and many people would say they were ‘Celts’. There are many debates in archaeology about whether the people of Britain (and Ireland) were related through genes or language to the originals Celts (who lived around Austria, Switzerland and southern France). The safe call is to refer to them as Iron Age Britons (or Iron Age Irish – the Iron Age in Ireland is usually treated separately to Britain’s).
From studies of the skeletons of Iron Age Britons we know that the average woman was 1.5 metres (5 foot 2 inches) in height, the smallest known was 1.4 metres (4 foot 9 inches) tall, and the tallest 1.7 metres (5 foot 7 inches). The average man was 1.69 metres (5 foot 6 inches) in height, the smallest known was 1.6 metres (5 foot 2 inches) tall and the tallest was 1.8 metres (5 foot 11 inches). There are few human skeletons from Iron Age Britain, but there is evidence for differences in height and health between people living in different parts of the country. People in East Yorkshire living about 400-100 BC were taller than people from Hampshire, for example.
A map showing the known Iron Age tribes and where they lived.
Art and culture
In the earlier Iron Age, we see pottery and metalwork in the Hallstatt style. That is the dominant style of central Europe. Hallstatt is superseded by La Tené style in Europe and Britain. Here La Tené develops local character, called ‘Insular Curvilinear’, which is what most people think of as ‘Celtic’.
Society and Conflict
We know from Roman writings (e.g. Julius Caesar and Tacitus) that Britons had tribal groups. The Atrebates occupied an area in modern Hampshire north of Butser Hill. The Romans tell us that the tribes often fought each other. Aside from their tribal Kings and Queens, they had Druids – powerful spiritual leaders with authority in some matters of law, war and peace. By the time of Julius Caesar’s invasions of 55 and 54 BC the Britons were well organised fighters, suggesting they were used to fighting their own, domestic battles.
The end of the Iron Age
We don’t know if these changes in culture and art happened through the actual movement of people or just the transfer of ideas. Hillforts and the introduction of new styles of pottery, as well as metalwork has led some archaeologists to think there were invasions; others see the changes as an adoption of ideas (from the continent) and only a few new people(s) moving into British Isles.
By the late Iron Age, Britain is a prosperous land, partly thanks to limited trade with Rome. In BC 55, Julius Caesar made an aborted invasion of Britain, possibly to punish the Britons who had been aiding the Gauls in their fight against Roman rule. Over the next decade the diplomatic influence of Rome, in Britain, increased as did trade. Rome exploited disputes between various tribes in southern Britain and, ultimately, in 43 AD Britain is conquered by the Romans under the Emperor Claudius.