Ireland: history to 1154

There is some debate about the date of the earliest human occupants of Ireland. Various sites, such as that at Larne, had suggested that a Mesolithic culture, based on hunting and fishing, was established by around 6000 BC. However, it is now thought that these hunting and fishing people may have been contemporary to the Neolithic communities and megalith builders, who arrived at the beginning of the 3rd millennium BC. The Irish megalith builders developed the passage tomb, some of the most remarkable of which are found at Newgrange, where the main passage is aligned to the winter solstice. In the Bronze Age Ireland held an important position, trading gold ornaments, such as torques (armbands and bracelets), all over Europe.

The arrival of the Celts
The Iron Age witnessed the arrival of the Celts, and it is thought that the Celtic La Tène culture may have been established by around 300 BC. Even after the Celtic settlement of Ireland great numbers of the earlier inhabitants survived, and intermarriage between the Celtic and pre‐Celtic tribes took place to an even greater extent than was customary in other lands settled by the Celts. The Alexandrian geographer Ptolemy (2nd century AD) gives the names of at least 16 tribes in Ireland. These names bear a strong resemblance to the tribal names of the Celts in Britain, for example the name ‘Brigantes’ is found in both countries. Ireland was known to the Romans as Hibernia, but no invasion was ever attempted.

The early Christian era
By the early centuries AD Ireland was inhabited not only by Irish Celts and pre‐Celtic peoples, but also by some Picts, who probably came from Scotland, and the five kingdoms of Ireland (Ulster, Meath, Leinster, Munster, and Connacht) had emerged. These kingdoms were nominally subject to an ard‐rí or high king; the chiefs were elected under the tribal or Brehon law, and were usually at war with one another. The medieval Irish historians claimed that the country had reached a high state of civilization prior to the coming of St Patrick in the 5th century (see below). The Irish are described as a martial and cultured people who, in an age when most of Europe was still in an uncivilized state, held their poets and historians in equal reverence with their royal chiefs. Centuries before the Christian era, they are said to have established a Feis, or central parliament, which assembled triennially at the high king's court on the Hill of Tara. While the names and alleged deeds of the earliest high kings of Ireland have been preserved, the first of real historical importance is Niall of the Nine Hostages (late 4th–early 5th centuries). He is said to have finally set up the central kingdom of Tara and to have led expeditions of the Irish overseas. Ireland and Wales were closely connected at this period, and the expeditions of Niall of the Nine Hostages synchronize with the departure of the Romans and the raids of the Picts and Scots into southern Britain. Irish colonies were formed in Wales, Devon, and Cornwall around this time.

The coming of Christianity
Christianity was introduced by St Patrick in the mid‐5th century, and during the 5th and 6th centuries, Ireland became a centre for sending out missionaries to Britain and Europe. Christianity had been the official religion of the Roman Empire for a century, and the Irish and Romano‐Britons had for a long time been in close contact, so it is reasonable to suppose that Christianity was known and practised among the Irish to some extent before the coming of St Patrick. But the number of Christians in Ireland was probably small, and largely confined to the south, and there were no organized churches. St Patrick – already familiar with Irish language and customs from a period spent in slavery in Ireland – seems to have directed his efforts to the north and west. He took with him at least two followers who spent their time in the south, spreading the gospel and organizing churches. His approach was to convert the tribal chiefs, and then the new beliefs would be adopted by their people, from among whom would come new priests to carry on the work of conversion. St Patrick had considerable success, but his influence has certainly been exaggerated by later writers.

The development of the church in Ireland
The spread of Christianity was accompanied by the building of schools and churches, and the see of Armagh (where Patrick had been archbishop) became connected with the Roman Church. Bishops were consecrated and the land was divided into dioceses, which probably coincided with tribal divisions. The Irish (or Celtic) Church, during the centuries that followed, was to develop along strongly monastic lines, and religious colonies originating from one centre became and remained daughter settlements of the parent body. The head of a religious foundation was the possessor of both spiritual and temporal rights, and frequently the headship of a religious foundation passed entirely into lay hands. The early form of monasticism in Ireland seems to have been somewhat loose, and to have led to much disorder. Further, the Irish bishops did not have any territorial jurisdiction, and the consequence was that the number of bishops was very large. Judged by the standards of Western Europe the church in Ireland was morally somewhat lax, but this was probably due as much to the struggle between the old and new religions as to anything else. The foundation of the monastery at Clonard in the early 6th century by St Finnian marks the beginning of a series of monastic foundations that made Ireland the centre of learning for Western Europe. These monastic settlements were conducted on lines very much more severe than the earlier ones had been. The monks were shut off entirely from the laity, and the sexes were separated.

Irish missionaries abroad
This monastic movement was accompanied by much missionary enterprise, and missionaries of the Celtic Church went everywhere. In the 6th century St Columba went to Iona, from where Scotland was converted. The Saxon kingdoms in the north and centre of England owed their conversion to Irish missionaries from Iona; St Aidan became the first Bishop of Northumbria, and was succeeded in the monastery of Lindisfarne by two other Irish monks. St Columban took a mission to Western Europe. In the Orkneys the Celtic Church was established, and Iceland, when discovered by the Vikings, was found to have been visited previously by missionaries of the Celtic Church. The Irish missionaries had brought learning as well as religion, and Northumbria became the cradle of Anglo‐Saxon literature. The Irish missionaries soon found themselves differing from those of Rome in such matters as the type of tonsure worn and the calculation of Easter, and in 664 the Synod of Whitby decided to adopt the Roman rather than the Celtic form of Christianity for Britain. Nevertheless the Irish missionary effort in Europe endured up to the 12th century. Irish nationalism views this period as the ‘Golden Age’ of Irish history. The Irish were a strong and settled people, free from the interference of Britain. They achieved much and, for a time, formed the cultural and religious centre of Europe. From this age comes the legend of the heroic fighter Finn Mac Cumhaill, who gave his name to the Fenian movement, fighters for Irish independence in the 19th century. Irish nationalists see how successful Ireland was when it was independent, and trace the decline in Irish power and influence to the loss of independence that came at the end of this golden era. The roots of the Irish people, being Celtic and Pict give Irish nationalists the view that the Irish are separate from the English, being of a different ethnic background. Again the consequences of this golden age and the preceding centuries are used to promote Irish nationalism in the modern era.

The decline of the high kings, 5th–8th centuries
Until the 8th century the political history of Ireland is one of ongoing and practically uninterrupted tribal warfare. The descendants of Niall of the Nine Hostages remained high kings of Ireland until the beginning of the 11th century, but were seldom powerful enough to be able to maintain peace in the country. The church was not strong enough to perform the work of the high kings, and moreover the personal character of church government made the church often a party to the quarrels of the tribes. The descendants of Niall of the Nine Hostages were divided into two great branches, the southern Hy Niall and the northern Hy Niall. At the end of the 5th century the Scots, a people from the north of Ireland, made their settlements in Argyllshire, which they called Dalriada, and ultimately, after strenuous struggles, obtained the crown of a more or less united Scotland in the 9th century (see Scotland: history to 1058). About the middle of the 6th century Tara ceased to be the residence of the high kings. While many legends are connected with the desertion of this centre, the records tell us only of constant wars, successions, and short reigns. The country was in a state of anarchy, and the attempt to rule Dalriada (Argyllshire) as a subject kingdom of the high king of Ireland was abandoned. The position of the high king was unenviable. He could command no real allegiance save that of his own immediate tribe. The army of Ireland consisted of the tribes commanded by their own chiefs. The chiefs owed allegiance to the high king, but allegiance of such a shadowy type that it counted for nothing. Such was the state of Ireland when the Vikings began a series of raids that were to develop into permanent settlement.

The Viking invasions
The first invasion of the Norsemen or Vikings occurred towards the end of the 8th century. Monasteries were frequent targets for Viking raids, offering riches and provisions. The Norwegians were the first to arrive, and, aided later by the Danes, they established settlements on the east coast, founding Dublin and other coastal towns. The domination of Ireland by the invaders for over a century was not altogether a misfortune, since it brought that country into closer contact with the culture of Western Europe. Many of the Irish tribes fought in the armies of the Danes who invaded England. Foreign trade, especially with Scandinavia, flourished.

Brian Bóruma and his successors
After the middle of the 10th century a powerful Irish prince emerged, Brian Bóruma (or Boru), king of Munster, who defeated the Danes and forced them into the position of a subject people. After bitter struggles with the reigning dynasty, Brian managed in 1002 to become high king himself, and during the 12 remaining years of his life he ruled a peaceful and prosperous Ireland. But he had still to face the hostility of the Danes and the jealousies of the Irish chieftains. In 1014 the Battle of Clontarf finally broke the power of the Danes, although Brian himself was killed. Brian's death was a serious blow to the monarchy in Ireland, and led in the century or more following his death to internecine strife and the weakening of central power. The history of Ireland from the Battle of Clontarf to the Anglo‐Norman invasion in the 12th century is a record of continual strife between the O'Briens of Munster, the O'Neills of Ulster, and the O'Connors of Connacht for the high kingship of Ireland. Relations with England during this period were not close but remained generally friendly.

The establishment of a national church
The fragmented state into which the Irish Church had fallen was largely remedied at the Synod of Kells in 1152, which established four archbishoprics (one of them in Dublin, which as a Danish bishopric had been subject to the see of Canterbury in England), and which did much to abolish the anarchic state of church government. The church had remained, however, sufficiently strong to produce numbers of devoted clerics, aware of the need for reform. Notable among these was St Malachy (1094–1148), abbot of the monastery of Bangor and bishop of Connor, who set about organizing definite dioceses. This work, which had been begun previously by Gilbert, bishop of the Norse of Limerick, and Celsus, bishop of Armagh, and carried on by Malachy, was completed at the Synod of Kells. A national church arose, and the unity of the church in Ireland was clearly established under a recognized primate (national church leader). The other great reform to which Malachy devoted himself was the revival and reform of the monasteries. The Canons Regular and the Cistercians, who practised the severe discipline established by the Irish missionaries in Europe, were employed by Malachy to restore the old monastic spirit in Ireland, and for that purpose he brought communities from Europe and sent Irish students to be trained in European monasteries.

For subsequent events in Irish history, see Ireland: history 1154 to 1485, Ireland: history 1485 to 1603, Ireland: history 1603 to 1782, and Ireland: history 1782 to 1921. For events after 1921, see Ireland, Republic of and Northern Ireland.