THE BROCH CULTURES OF ATLANTIC SCOTLAND. PART 2. THE MIDDLE IRON AGE: HIGH NOON AND DECLINE c.200 BC–AD 550

The basic features of broch architecture are discussed. There were probably a large number of classic, hollow-walled, dry-stone towers, as opposed to lower, less architecturally sophisticated 'Atlantic roundhouses'. Various kinds of dating imply that most were built – probably by professionals – in the Middle Iron Age, from c.100 BC to AD 200, although a few emerged earlier in Shetland, perhaps from 400–300 BC. Wheelhouses seem to have emerged from these early Shetland brochs. The MIA material culture includes many new items found all over the province, though much of the pottery is regional. Everted Rim ware was clearly connected somehow with the spread of the brochs from Shetland. The details of the MIA mixed farming economy are reviewed, as is the varied if indirect evidence for the social organization of the broch families; a hierarchical clan society is implied. The MIA now seems to have lasted until the sixth century AD and in the west at least its end may have been precipitated by a drastic climatic downturn.