The early medieval period
The beginnings of history in Ireland coincide roughly with the introduction of both Christianity and writing in or about the early fifth century AD, though the record is very sparse for the first few centuries of the Christian era. Important churches were founded in due course close to Brú na Bóinne at Slane, Duleek and Monasterboice. On the political side this area was situated within the ancient territory of Brega, one of the many petty kingdoms or tuatha into which Ireland was divided in early medieval times. A branch of the powerful Southern UÁ Néill, the SÁl nAedo Sláine, established themselves at Knowth by about AD 800 and built their residence on the great passage-tomb mound. One member of this dynasty, Congalach, became king of Tara and high king of Ireland from 944 to 956. The Vikings raided Brega in the ninth century, but never founded a base here probably because of the power of the local kings.
The high medieval period
The twelfth century AD saw major changes in the Irish church with the establishment of territorial dioceses and the introduction of Continental monastic orders. The first Cistercian monastery in Ireland was founded at nearby Mellifont in 1142 and much of the land in the Bend of the Boyne was granted to this new foundation. The farming of these lands was organised from centres known as granges and initially one was founded on the mound at Knowth. By the fourteenth century a new farm centre was established further to the east and became known as the New Grange, and hence the name by which we know the most famous of the three large passage tombs. A large part of Ireland was conquered by the Anglo-Normans in the late twelfth and early thirteenth centuries and new lordships centred on castles were established across the country. Motte-and-bailey castles were constructed at Drogheda and Slane and the passage tomb mound at Knowth appears to have been used for a time as a motte.
New settlers and the rediscovery of Newgrange
At the suppression of the monasteries under Henry VIII about 1540 monastic property such as the land around Knowth and Newgrange was leased by the state to lay people and this process and the Cromwellian plantation of the mid-seventeenth century brought new English landowners and settlers into this area. Quarrying activities at the mound of Newgrange in 1699 by the owner Charles Campbell led to the rediscovery of the passage and chamber and fortunately they were described and drawn by the Welsh antiquary, Edward Lhwyd, that same year. Many other antiquaries visited the tomb over the following two centuries and various theories were propounded as to its date and purpose.
State protection and World Heritage listing
The tumuli of Newgrange, Knowth and Dowth were listed for protection as National Monuments in a schedule attached to the Ancient Monuments Protection Act, 1882. It was some time before they were formally taken into State care and more recently still before they were purchased outright by the State with adjoining land. Major archaeological excavations, followed by conservation and presentation works, have been carried out in the late twentieth century at both Newgrange and Knowth and both have become major visitor attractions. The entire complex of monuments at Brú na Bóinne was added to the World Heritage List in 1993 and a new visitor centre was opened across the river Boyne from the cemetery in 1997.