Hill of Tara

The oldest visible monument is Dumha na nGiall, the Mound of the Hostages, a Neolithic passage tomb built around 3,200 BC. For about a century it was the communal tomb of a single community, taking almost 300 burials. Almost a millennium later, in the Bronze Age, a further 33 burials were placed there, and by then only certain high-status individuals were buried in it; two gold torcs found at the tomb date to around 2000 BC.

The large round enclosures came later, in the Iron Age. The biggest and most central, Ráth na Ríogh, the Enclosure of the Kings, is dated to the 1st century BC, and human burials, together with a high concentration of horse and dog bones, were found in its ditch. Just to the north, Ráth na Seanadh, the Rath of the Synods, was occupied between the 1st and 4th centuries AD and yielded Roman artefacts.

Early Irish literature records a royal gathering, the feis Temro or feast of Tara, held on the hill at Samhain. By the beginning of Ireland's historical period Tara had become the seat of a sacral kingship, and the historian Dáibhí Ó Cróinín writes that it "possessed an aura that seemed to set it above" the other royal seats. Tradition identifies the hill as the inauguration place and seat of the High Kings of Ireland, and medieval king lists traced that line far into the past, though John T. Koch cautions that "in political terms it is unlikely that any king had sufficient authority to dominate the whole island before the 9th century". A standing stone on the Forradh, or Royal Seat, within Ráth na Ríogh is believed to be the Lia Fáil, the Stone of Destiny at which the High Kings were crowned.

Tara was probably controlled by the Érainn before the Laigin seized it in the third century, and Niall of the Nine Hostages displaced the Laigin in the fifth, after which the hill became the ceremonial seat of the Uí Néill. Medieval writers gave particular weight to the reign of Diarmait mac Cerbaill, a historical king of Tara in the sixth century, who was probably pagan but was also influenced by Christian leaders and who "stood chronologically between two worlds, the ancient pagan one and the new Christian one". The kingship alternated between the Southern and Northern Uí Néill until the eleventh century, after which control of Dublin, Limerick and Waterford mattered more to a would-be High King than control of Tara. The Irish annals record the Battle of Tara in 980 between the Gaelic Irish of Meath, led by Máel Sechnaill mac Domnaill, and the Norse Vikings of Dublin, led by Amlaíb Cuarán.

The earliest evidence of a church at Tara is a charter dating from the 1190s, and in 1212 the church was among the possessions confirmed to the Knights Hospitallers of Saint John of Kilmainham by Pope Innocent III. The present St Patrick's, on the eastern side of the hilltop, was built in 1822–23 on the site of the earlier church and re-used some of its stonework.

During the rebellion of 1798 the United Irishmen formed a camp on the hill, and British troops attacked and defeated them there on 26 May; the Lia Fáil was allegedly moved to commemorate the 400 rebels who died on the hill that day. In 1843 the Irish nationalist leader Daniel O'Connell hosted a peaceful political demonstration at Tara in favour of Irish self-governance which drew over 750,000 people.

At the turn of the twentieth century a group of British Israelites, who held that the British were part of the Lost Tribes of Israel and that the hill contained the Ark of the Covenant, paid off the landowner Gustavus Villiers Briscoe and set about excavating the site, led by Edward Wheeler Bird, a retired Anglo-Indian judge. The digging badly mutilated the Rath of the Synods. Irish cultural nationalists held a mass protest over the destruction of the national heritage site, among them Douglas Hyde, Arthur Griffith, Maud Gonne, George Moore and W. B. Yeats; Hyde was ordered away from the dig by a man wielding a rifle, and Gonne relit a bonfire Briscoe had lit for the coronation of Edward VII, singing Thomas Davis's "A Nation Once Again" beside it.

The Irish government bought the southern part of the hill in 1952 and the northern part in 1972, and Tara is a protected national monument under the care of the Office of Public Works, which also operates the former church as a visitor centre. On 23 September 2007 over 1,500 people met on the hill to form a human sculpture spelling out "SAVE TARA VALLEY", a call for the re-routing of the M3 motorway away from Tara; the World Monuments Fund placed Tara on its 2008 Watch List of the 100 Most Endangered Sites. The motorway opened in June 2010 on a line 2.2 km from the hill.