Early Viking raids
The early Vikings were a group of people who originated in modern-day Denmark and Norway. In the 700s, pressure on land in Scandinavia had forced many nobles and warriors to seek land elsewhere. Some of these were younger sons, who stood to inherit nothing of their father's estate. Noblemen with little to lose began to gather together groups of warriors and go down the coast pillaging settlements.
The first recorded Viking raid in Irish history occurred in AD 795 when Vikings, possibly from Norway looted the island of Lambay. This was followed by a raid on the coast of Brega in 798, and raids on the coast of Connacht in 807. These early Viking raids were generally small in scale and quick.
These early raids interrupted the golden age of Christian Irish culture and marked the beginning of two hundred years of intermittent warfare, with waves of Viking raiders plundering monasteries and towns throughout Ireland. Most of the early raiders came from the fjords of western Norway. They are believed to have sailed first to Shetland, then south to Orkney. The Vikings would have then sailed down the Atlantic coast of Scotland, and then over to Ireland. During these early raids the Vikings also travelled to the west coast of Ireland to the Skellig Islands located off the coast of County Kerry. The early raids on Ireland seem to have been aristocratic free enterprise, and named leaders appear in the Irish annals: Saxolb (Soxulfr) in 837, Turges (Þurgestr) in 845, Agonn (Hákon) in 847.
Intensified raiding and the first Viking settlements in Ireland
The Viking raids on Ireland resumed in 821, and intensified during the following decades. The Vikings were beginning to establish fortified encampments, longports, along the Irish coast and overwintering in Ireland instead of retreating to Scandinavia or British bases. The first known longports were at Linn Dúachaill (Annagassan) and Duiblinn (on the River Liffey, at or near present Dublin). They were also moving further inland to attack, often using rivers such as the Shannon, and then retreating to their coastal bases. The raiding parties also increased in size, becoming regular armies—in 837 the annals report a fleet of sixty longships on the Liffey, carrying 1.500 men, and another one of a similar size sailing up the river Boyne, making their way into the inland territories and launching attacks on the lands of Brega in the south of County Meath. In general, from 837 onward larger Viking forces hit larger targets - such as the greater monastic towns of Armagh, Glendalough, Kildare, Slane, Clonard, Clonmacnoise, and Lismore - while smaller targets such as local churches with less material to be plundered may have escaped the Vikings' attention.
A significant new trait from the middle of the 9th century was that the Norse now also entered alliances with various Irish rulers. Cerball mac Dúnlainge had become king of Osraige in 842. Cerball had defeated Viking raiders in 846 and 847, but from 858 he is allied with Olaf and Ivar against Máel Sechnaill, campaigning in Leinster and Munster, and in 859 also raiding Máel Sechnaill's heartlands in Mide, though Cerball had to submit to Máel Sechnaill later the same year. These alliances were by no means permanent. In 860 Cerball was allied with Máel Sechnaill in a campaign against Áed Findliath of the Northern Uí Néill, while Olaf and Ivar has allied themselves with Áed. In 870, however, Cerball and Áed appeared as allies in Leinster.
A new and more intensive period of Viking settlement in Ireland began in 914. Between 914 and 922 the Norse established Waterford, Cork, Dublin, Wexford and Limerick. Significant excavations in Dublin and Waterford in the 20th century have unearthed much of the Viking heritage of those cities. A large amount of Viking burial stones, called the Rathdown Slabs, have been found in multiple locations across South Dublin.
The Vikings founded many other coastal towns, and after several generations of coexistence and intermarriage a group of mixed Irish and Norse ethnic background arose (often called Norse-Gaels or Hiberno-Norse).
They are believed to have sailed first to Shetland, then south to Orkney. The Vikings would have then sailed down the Atlantic coast of Scotland, and then over to Ireland, Isle of Man, England, and Wales.
“HAAGDYVE (Word origin): Derived from the "Norm" language. ” — Dr. M. Williams
Norn is an extinct North Germanic language that was spoken in the Northern Isles (Orkney and Shetland) off the north coast of mainland Scotland and in Caithness in the far north of the Scottish mainland. After Orkney and Shetland were pledged to Scotland by Norway in 1468/69 it was gradually replaced by Scots. Norse settlement in the islands probably began in the early 9th century. These settlers are believed to have arrived in very substantial numbers and like those who migrated to Iceland and the Faroe Islands it is probable that most came from the west coast of Norway. Shetland toponymy bears some resemblance to that of northwest Norway, while Norn vocabulary implies links with more southerly Norwegian regions.