Sunday, October 26, 2008
Professor Ian Ralston, Professor of Archaeology, University of Edinburgh
It is impossible in a written report to convey the dramatic visual impact of the large number of excellent colour slides used by Professor Ian Ralston to illustrate his lecture to the Inverness Field Club.
Professor Ralston drew from his long experience culminating in the Professorship of Archaeology at University of Edinburgh to demonstrate the many and varied links between the structure of hill forts in Scotland and those in the rest of Great Britain and different parts of mainland Europe. Latest estimates are that there are about 20,000 hill fort sites in Europe of which some 1,000 are in Scotland. Maiden Castle in Dorset is a typical upland site with a very imposing set of banks and ditches designed in a warrior context to help both with attack and defence. These are now grassed over but when first constructed the gleaming white chalk would have presented a formidable appearance. In Ireland certain hill forts are traditionally associated with resistance to the arrivals of peoples speaking Celtic languages. In a later period the conflict between Iron Age people and Roman invaders in the first century BC is demonstrated not only by the archaeological record but also by textual references such as the account by Julius Caesar of the wars in Gaul. At Alesia Roman siege works surrounded the Iron Age fort prior to the decisive battle, which led to the Roman conquest of Gaul. At that time hill forts were very widely distributed throughout Europe and were not confined to Celtic areas. Brochs were the only structures that were unique to Scotland. There is evidence going back to the bronze shields of the Bronze Age, prior to 1,000 BC, that warfare was very much an aristocratic pursuit with warriors having fine parade equipment. By the end of the period the archaeological record shows that individual named people such as Vercingetorix can be linked to specific sites.
A basic text is Hillforts of Britain, by A.H.A. Hogg, 1975. Hogg identifies four types of hill fort: Contour forts, promontory forts, cliff forts and ridge forts. This classification is not very precise. Contour forts where banks and ditches are moulded to the shape of the hill are the dominant ones in Scotland. Promontory forts, such as the largest one in Scotland at the Mull of Galloway, are usually a coastal feature. As their name implies, cliff forts are on the top of cliffs. Ridge forts often have a route way through them. There is a large variation in the size of these hill forts from the enormous to the minute. Some large upland sites in south west Germany and France extend to 1,000 hectares (2,400 acres), i.e. larger than the site of classical Rome. The largest sites were defendable blocks of upland country surrounded by cliffs. Sites at a low altitude often had a dense population within their perimeter. By contrast a few sites are at an extremely high altitude. In county Sutherland it is well worth ascending to the remarkable remains in a very exposed situation on top of Ben Griam Beg 2,000 feet above sea level. There is even evidence of some external settlement outside the fort. In Ireland, Caherconree fort in county Kerry is at an altitude of 2,700 feet but it is unlikely to have witnessed any permanent settlement. The date range of hill forts extended over 2,000 years. Early examples in Germany date from the late Bronze Age about 2,000 BC whereas forts from the Slav part of Europe were constructed as late as the 9th Century AD. Nearby the fort at Burghead dates from the first millennium AD but it has subsequently been badly depleted. In some areas burrowing by rabbits has caused more destruction than human activities!
Different types of defensive style occur throughout the Iron Age period. In later years they were a response to Roman siege warfare. There are different combinations in the use of earth, stone or timber. Timber is frequently infilled with stone or other materials. In Europe the timber is often arranged vertically but in Scotland horizontal timbers predominated. The use of timber increased the risk of damage by fire. There is evidence in Europe that styles were copied from classical Greece although the purpose of certain military features such as vertical stone walls with bastions was not fully understood. Some styles appeared formidable but they were not truly defensive because access to the forts remained open at the sides or rear. This was the case with certain forts in Shetland.
In Scotland certain sites are difficult to dig because they continue to be in use. Obvious examples are the castles at Edinburgh and Stirling. At Bourges in France the Iron Age remains are now five metres below the surface. Many rural sites are still easily available for study from actual remains or from crop mark records. Quarry working has destroyed certain sites such as Broxmouth in East Lothian. At Broxmouth there was evidence that stone-built houses replaced timber houses about 200 BC and that the hill fort settlement was replaced by an unenclosed settlement. Traded Roman coins are evidence of a Celtic reoccupation of upland forts in Roman times. Traprain Law is the largest surviving hill fort in Scotland although it is only 16 hectares in extent. It goes back to the Bronze Age and it was there that the Traprain Law silver treasure dating from Roman times was found. Other large hill forts in Scotland were Dunagoil in Bute, Eildon Hill North dating from the Bronze Age and the Tap O'Noth. Elsewhere in Europe hill forts were abandoned and many people moved to live in oppida or towns established under Roman rule.
One intriguing subject is the origin of vitrified forts. They are forts where heat has transformed the surface of the stone to glass. Vitrification is witness to the systematic deliberate destruction by fire of conquered sites in the early part of the first millennium AD. To the local people it would have been a spectacular intimation of power. Good local examples are Craig Phadraig above Inverness and Knockfarrel near Strathpeffer. A series of dramatic slides illustrated experiments in 1980 to reproduce the process of vitrification. A wall constructed with stone and horizontal timers was set alight and kept burning vigorously throughout the night. By morning the wall had become unsafe and some vitrification had taken place.
In conclusion there were significant differences between Scotland and the rest of Europe. In Scotland many of the early sites were very large as at Eildon Hill North and Tap O'Noth. Their construction represented a large social effort. They date from the late Bronze Age and are separated by a gap from later occupation coinciding with the Roman period. In Scotland it is the early sites that are big in contrast with Europe where the larger sites are later. In Europe a money economy developed, the leaders began to live in large houses and the style of living became more luxurious with features such as the increasing use of wine. In Europe it was a civilised society that the Romans took over and enhanced. By contrast Scotland was too difficult for the Romans to take over and absorb.