The Norse King Glúniairn recognises Máel Sechnaill mac Domnaill, High King of Ireland, and agrees to pay taxes and accept Brehon Law; the event is considered to be the founding of the city of Dublin.
Early Irish law, historically referred to as Fineachas (English: Freeman-ism) or Dl na Fine (English: Law of Freemen), also called Brehon law, comprised the statutes which governed everyday life in Early Medieval Ireland. They were partially eclipsed by the Norman invasion of 1169, but underwent a resurgence from the 13th until the 17th century, over the majority of the island, and survived into Early Modern Ireland in parallel with English law. Early Irish law was often mixed with Christian influence and juristic innovation. These secular laws existed in parallel, and occasionally in conflict, with canon law throughout the early Christian period.
The laws were a civil rather than a criminal code, concerned with the payment of compensation for harm done and the regulation of property, inheritance and contracts; the concept of state-administered punishment for crime was foreign to Ireland's early jurists. They show Ireland in the early medieval period to have been a hierarchical society, taking great care to define social status, and the rights and duties that went with it, according to property, and the relationships between lords and their clients and serfs.
The secular legal texts of Ireland were edited by D. A. Binchy in his six-volume Corpus Iuris Hibernici. The oldest surviving law tracts were first written down in the seventh century and compiled in the eighth century.
Glúniairn (died 989), in Old Norse Járnkné ([ˈjɑːrnˌkneː], "Iron-knee"), was a Norse-Gael king of Dublin of the Uí Ímair kindred which ruled over much of the Scandinavianised and Norse-Gael parts of Great Britain and Ireland in the tenth century.
Glúniairn was a son of Amlaíb Cuarán (d. after 980) who abdicated as king of Dublin following his defeat at the Battle of Tara in 980 and the subsequent capture of Dublin by Máel Sechnaill mac Domnaill of Clann Cholmáin, the High King of Ireland. Olaf retired to Iona where he probably became a monk and later died. Glúniairn and Máel Sechnaill were both sons of Dúnlaith, sister of the previous High King, Domnall ua Néill of Cenél nEógain, and Máel Sechnaill appointed his half-brother to rule in Dublin as his client. Máel Sechnaill removed many of the hostages and captives that Amlaíb Cuarán had held in Dublin, including Domnall Clóen, King of Leinster.It is likely that Glúniairn benefited substantially from the support of his half-brother, and this support extended beyond that which placed him in power in Dublin in 980 over the claims of his many half-brothers. Domnall Clóen, together with Glúniairn's distant kinsman Ivar of Waterford, faced Máel Sechnaill and Glúniairn in battle in 983, and defeated their enemies, Ivar's son Gilla Pátraic being one of the many dead in this rout. Máel Sechnaill's army ravaged across Leinster while Glúniairn's men attacked the church at Glendalough.In 989 Glúniairn was "killed when drunk by his own slave", his killer's name being given as Colban in Dubhaltach Mac Fhirbhisigh's Chronicon Scotorum. Benjamin Hudson suggests that the reports of the killing in the Irish annals, and particularly Máel Sechnaill's rapid riposte, argue that Glúniairn's death was more probably the result of factional infighting in Dublin. The annals record that Máel Sechnaill attacked Dublin, brushing aside resistance. He demanded, and received, the payment of eraic, a term in early Irish law corresponding approximately with Anglo-Saxon wergild. He retained a third for himself, which is what the law would prescribe for a ruler or nobleman acting to enforce payment. It is unclear if Glúniairn was succeeded by Sigtrygg Silkbeard, his paternal half-brother, or by the rival Ivar of Waterford.
Glúniairn had at least one full sibling, a sister named Ragnhild who married a son of Congalach Cnogba. Glúniairn's son Gilla Ciaráin died in 1014 at the battle of Clontarf. He had a second son, who may have been called Sitriuc, who is recorded as killing Gofraid, son of Sigtrygg Silkbeard, in Wales in 1036. This son was perhaps the father of Gofraid (died circa 1070), a ruler of the Isle of Man who is said to have given refuge to Godred Crovan. This Gofraid had a son named Fingal who also ruled Man and died in 1079. Some interpretations would make Macc Congail, who ruled the kingdom of the Rhinns, Fingal's son.