The word
broch is derived from
Lowland Scots 'brough', meaning (among other things) fort. In the mid-19th century Scottish
antiquaries called brochs 'burgs', after
Old Norse '
, with the same meaning. Place names in Scandinavian Scotland such as Burgawater and Burgan show that Old Norse ' is the older word used for these structures in the north. Brochs are often referred to as
dùn in the west. Antiquarians began to use the spelling
broch in the 1870s. A precise definition for the word has proved elusive. Brochs are the most spectacular of a complex class of roundhouse buildings found throughout Atlantic Scotland. The
Shetland Amenity Trust lists about 120 sites in
Shetland as candidate brochs, while the
Royal Commission on the Ancient and Historical Monuments of Scotland (RCAHMS) identifies a total of 571 candidate broch sites throughout the country. Researcher Euan MacKie, using a restricted definition, has proposed a much smaller total for Scotland of 104. broch,
Lewis, Scotland The origin of brochs is a subject of continuing research. Eighty years ago most archaeologists believed that brochs, usually regarded as the 'castles' of Iron Age chieftains, were built by immigrants who had been pushed northward after being displaced first by the intrusions of
Belgic tribes into what is now southeast England at the end of the 2nd century BC and later by the
Roman invasion of southern Britain beginning in AD 43. Yet there is now little doubt that the hollow-walled broch tower was an invention in what is now Scotland; even the kinds of pottery found inside them that most resembled south British styles were local hybrid forms. The first of the modern review articles on the subject (MacKie 1965) did not, as is commonly believed, propose that brochs were built by immigrants, but rather that a hybrid culture formed from the blending of a small number of immigrants with the native population of the Hebrides produced them in the 1st century BC, basing them on earlier, simpler, promontory forts. This view contrasted, for example, with that of Sir
W. Lindsay Scott, who argued, following
V. Gordon Childe (1935), for a wholesale migration into Atlantic Scotland of people from southwest England. MacKie's theory has fallen from favour too, mainly because starting in the 1970s there was a general move in archaeology away from 'diffusionist' explanations towards those pointing to exclusively indigenous development. Meanwhile, the increasing number – albeit still pitifully few – of
radiocarbon dates for the primary use of brochs (as opposed to their later, secondary use) still suggests that most of the towers were built in the 1st centuries BC and AD. A few may be earlier, notably the one proposed for
Old Scatness Broch in Shetland, where a sheep bone dating to between 390 and 200 BC has been reported. The other broch claimed to be substantially older than the 1st century BC is
Crosskirk in Caithness, but a recent review of the evidence suggests that it cannot plausibly be assigned a date earlier than the 1st centuries BC/AD. ==Distribution==