The earliest evidence we currently have for human activity in Ireland dates to around 7000 BC. From then until around the early centuries AD, when our knowledge of the people of Ireland is enhanced by written records, the physical remains left in the landscape are the only sources of information about our prehistoric ancestors. Of all the remains left behind by these people, their burial monuments have provided us with our most prolific source of artefacts and human remains and much of what we know about the prehistoric people of Ireland comes from this source.
The most visible of the burial monuments are megalithic tombs, which have usually dominated the discussion about prehistoric burial practices by virtue of their physical presence in the landscape. Megalithic tombs have been classified into four main types – portal, court, passage and wedge tombs – based on features unique to each type.
Portal tombs usually comprise a single, short chamber formed by two tall portal stones, two side stones and a back stone. Sometimes a stone between the portals closes the entry. The chamber is covered by a roof stone, often of enormous size, which slopes down from the front towards the rear. Cremation was the preferred burial rite and these date to the Neolithic, from around 3800 to 3200 BC.
Court tombs are generally long rectangular or trapezoidal cairns, at the broader end of which is usually an unroofed forecourt area which gave access to the roofed burial gallery which is placed axially within the cairn and divided into two to four chambers. The cairn was retained by a kerb of upright stones or drystone walling. Evidence indicates that the galleries were used for repeated burial, mostly cremations, over a long period of time. The sites date to the Neolithic, between 4000 and 3500 BC.
Passage tombs consist of a round mound usually surrounded by a kerb of large stones, enclosing a burial chamber, usually with a corbelled roof, which is entered by a passage which is usually lintelled. Many tombs have side and end recesses opening off a central chamber, resulting in a cruciform plan. Cremation was the predominant burial rite in passage tombs, which date from 3300 to 2900 BC, although some simpler tombs in Carrowmore, Co. Sligo, have produced radiocarbon dates suggesting they were in use even earlier, at around 4000 BC.
Wedge Tombs generally comprise a long burial gallery, sometimes with an antechamber or small closed end-chamber. They are usually broader and higher at the front, which invariably faces in a westerly direction. They are roofed by slabs laid directly on the side walls which often have one or more rows of outer walling. Evidence from the small number of excavated examples suggests that they were built during the Late Neolithic and Early Bronze Age periods (2500-2000 BC), during the last phase of megalithic tomb construction.
There are many other types of visible prehistoric monuments that are also associated with burials, such as cairns, henges and stone circles. A small number of boulder burials exist in the south-western part of the island. These usually consist of a large boulder or capstone, which rests on three or four supporting stones and which, in most cases, do not form a recognisable chamber structure. Excavations have suggested a Middle Bronze Age date for this burial monument, at around 1500-1300 BC.
There are many examples of monuments which are termed ring barrows, and comprise a circular or oval-shaped raised area (generally up to 1 m above the external ground level or level with it) enclosed by a fosse(s) and outer bank(s), with or without an entrance. These are part of the Bronze Age burial tradition but radiocarbon dating has indicated that they predominate during the Middle and Late Bronze Age and also extend into the Iron Age (1700 BC to AD 400).
Other sites, such as timber circles (2800-2500BC), may not now be visible in the landscape and are only revealed through excavation. Such large scale sites would undoubtedly have been very impressive when they were in use, as the reconstruction from Ballynahatty, Co. Down, clearly indicates.
In addition to these highly visible types of burial monument, prehistoric people in Ireland also buried their dead in the ground more discreetly, sometimes in a stone-lined box, or cist, or even in a simple urn without any associated mound or structure on the ground surface to mark its presence. A typical cist burial comprises a rectangular or polygonal structure, constructed from stone slabs set on edge and covered by one or more horizontal slabs or capstones. Cists burials may contain an inhumation, a cremation, or both. They may be built on the ground surface or sunk into the ground or set within a cemetery cairn or cemetery mound. They date to the mainly to the Early Bronze Age from around 2400 BC to 1500BC.
Cremation pits are burial sites in which the cremated remains of the corpse have been deposited; these are occasionally accompanied by burnt grave goods that would have been placed with the corpse on the pyre. They generally date from the Middle and Late Bronze Age, around 1500- 500 BC. A pit burial can vary from being an oval or sub-rectangular pit, large enough to accommodate a crouched inhumation, to a small circular pit with only enough space to accommodate a deposit of cremated bone or a cinerary urn. They usually date to the Bronze and Iron Ages, from around 2400 BC to AD 400, although pit burials have also been found to date from the Mesolithic period, for example, at Hermitage, County Limerick.
A substantial number of burial monuments, of all types, have been discovered in recent years during the construction of new roads and housing developments. The scientific analysis of these sites has significantly increased our knowledge of the people who would have lived and died in prehistoric Ireland.