The Orcadian broch builders

At one time, the accepted archaeological theory on the origin of the brochs was that they were built after an "invasion" of "broch builders" - people thought to have been people forced northwards by the Roman invasion of Britain.

Modern archaeology, however, has debunked this long-held idea.

Instead, the current thinking is that the people who constructed Orkney's brochs were simply farmers and fishermen - the descendents of the islands' Neolithic tomb builders.

They developed their dwellings in response to the needs of their time, not only providing a solid defensive structure, but probably also to allow them to show-off.

Raiders from the sea?

The fact that most Orcadian brochs were built by the coast has led to the suggestion they were constructed to defend against a sea-borne threat.

Early historians blamed the Romans, who they said, made trips north hunting slaves.

The most recent proponent of this theory is Shetland archivist, Brian Smith, who believes Iron Age Orkney was the centre of a vast Iron Age province, ruled over by a chieftain who co-ordinated a massive programme of defensive brochs to counter a threat from the south.

Mr Smith, who carried out an 18-month survey of brochs in Orkney and Shetland, proposes that these broch-builders had an enemy to the south, so constructed their fortifications in strategic positions, watching over harbours where an enemy might gain a foothold, as well as monitor huge expanses of sea.

The brochs are also found clustered around places where an enemy might co-ordinate an attack from east to west or north to south. Click here for more details.

However, as always, there are other suggestions as to the relevance of the broch's coastal locations. Perhaps most importantly, a coastal position allows easy access to the sea for fishing and transport and meant the structures could be built without wasting good agricultural land.

But the presence of external defences, comprising of ramparts and ditches, would certainly verify that brochs were built with some defence in mind.

Despite this, however, there is little or no evidence of fighting or of the violent destruction of a broch.

This has led to the idea that the broch dwellers lived in a society where feuds over lands and status were common - perhaps not surprising considering the small area involved - but that actual conflict rarely escalated above local squabbles.

Symbol of authority

The fact that brochs across Scotland are built to practically the same design led to the theory that they were the work of travelling master craftsmen.

These wandering artisans, it is suggested, undertook commissions from individuals, or families, wishing to signal their wealth and standing by constructing a broch.

But wandering craftsmen or not, what brochs do tell us is that Iron Age society was led by strong individuals, leaders who were anxious to broadcast their status and wealth to their rivals. An imposing broch provided an ideal method of doing this.

The brochs were designed to be impressive - an outward show of power, wealth and prestige. To build a broch required considerable manpower, so it was clearly apparent that anyone with a broch must have control, or influence, over a sizeable workforce.

This may have continued as far as the continual maintenance of the broch, which, it has been suggested, could have been organised to reinforce the superiority of the broch owner and maintain the social order within the village.

Abandoned

Over time, the defensive role of the brochs became unnecessary and the dwellers began moving outside the walls.

As the brochs were abandoned, their towering walls were often dismantled, providing a source of building material for the new dwellinghouses.

Orkney's Brochs and the Lothian Connection