Events from the 10th century in Ireland.

900s

;900 * Death of Tadg mac Conchobair, King of Connacht * Death of

Litan Litan (died 900) was abbot of Tuam. Litan was the fifth known abbot of Tuam, County Galway, but nothing else appears to be known of him. He was the apparent successor of Cormac mac Ciaran but because the sabbatical succession of Tuam is f ...

, abbot of Tuam ;902 * Dublin has been abandoned - the end of the

Longphort A longphort (Ir. plur. ''longphuirt'') is a term used in Ireland for a Viking ship enclosureConnolly S.J (1998). The Oxford Companion to Irish History. Oxford University Press. p. 580 or shore fortress. Although these ''longphorts'' were used as b ...

phase - the term used by modern scholars to refer to the earliest period of Viking settlement at Dublin ;904 *

Mughroin mac Sochlachan Mughroin mac Sochlachan was 30th King of Uí Maine, died 904). Mughroin mac Sochlachan is the first recorded king of Ui Maine since 844. He was the son of Sochlachan mac Diarmata and his brother's pedigree Murchadh mac Sochlachan (died 936) - wri ...

, 30th King of

Uí Maine U or u, is the twenty-first and sixth-to-last letter and fifth vowel letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''u'' (pro ...

, died. ;908 * 13 September - Flann Sinna slew Cormac mac Cuilennáin, the king-bishop of Cashel and King of Munster, at the battle of Belach Mughna, in Leinster. ;909 * Death of

Sochlachan mac Diarmata Sochlachan mac Diarmata (died 909) was 31st King of Uí Maine U or u, is the twenty-first and sixth-to-last letter and fifth vowel letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European la ...

, 31st King of

. * Death of Cerball mac Muirecáin, King of Leinster

910s

;911 *

Drogheda Drogheda ( , ; , meaning "bridge at the ford") is an industrial and port town in County Louth on the east coast of Ireland, north of Dublin. It is located on the Dublin–Belfast corridor on the east coast of Ireland, mostly in County Louth ...

is established as a Viking settlement on the River Boyne. ;911 or 914 *A large Viking fleet arrives in Waterford and a second period of Viking raids begins.''The Oxford Illustrated History of Ireland.'' Foster, RF. Oxford University Press, Oxford. 1989 The Vikings also established a base in Waterford. ;916 * 25 May: death of Flann Sinna (b 847 or 848), the son of Máel Sechnaill mac Máele Ruanaid of Clann Cholmáin, a branch of the southern Uí Néill. He was King of Mide from 877 onwards, following Donnchad mac Eochocain, and is counted as a

High King of Ireland High King of Ireland ( ga, Ardrí na hÉireann ) was a royal title in Gaelic Ireland held by those who had, or who are claimed to have had, lordship over all of Ireland. The title was held by historical kings and later sometimes assigned ana ...

* Death of Mór ingen Cearbhaill, Queen of Laigin. ;917 * The

Annals of Ulster The ''Annals of Ulster'' ( ga, Annála Uladh) are annals of medieval Ireland. The entries span the years from 431 AD to 1540 AD. The entries up to 1489 AD were compiled in the late 15th century by the scribe Ruaidhrí Ó Luinín, ...

records the arrival of two Viking fleets in Ireland in 917, one led by Ragnall and the other by

Sigtrygg Sigtrygg (''Sigtryggr'') is an Old Norse given name, composed of the elements ''sig'' "victory" and ''trygg'' "trusty, true". It is cognate with the Anglo-Saxon Sihtric. In Norse-Gaelic Ireland (9th to 11th centuries) rendered as ''Sitric'' or ' ...

, both of the Uí Ímair kindred. They fought a battle against

Niall Glundub Niall is a male given name of Irish origin. The original meaning of the name is unknown, but popular modern sources have suggested that it means "champion" (derived from the Old Irish word ''niadh''),. According to John Ryan, Professor of Early an ...

in which the Irish were routed, and according to the annals Sigtrygg then "entered Áth Cliath", i.e. Dublin, which we must assume means that he took possession of it. Ragnall Uí Ímair went on to Scotland, and then conquered York and became king there. ;919 *Niall Glúndub, overking of the Uí Néill, killed in the battle of Dublin. He fell fighting the Dublin Norse at Islandbridge.

920s

;922 *The Vikings establish a Longphort in Limerick. *Death of

Muiredach Mac Domhnaill Muiredach (Old Irish), Muireadhach or Muireach, anglicized variously to Murdoch (disambiguation), Murdoch, Murtagh, Murray (surname), Murray, Murdac, Mordacq and other forms, is a Goidelic languages, Goidelic name (meaning "chieftain") popular in S ...

, abbot of Monasterboice, under whose auspices the great high cross was made. ;925 *Death of Tadg mac Cathail, King of Connacht. ;926 or 941 * Brian Boru (d.1014), future High King of Ireland is thought to have been born in 926 or in 941. ;927 *Death of Sigtrygg Caech (or ''Sihtric''), a Norse-Gael King of Dublin who later reigned as king of York. His epithet means the 'Squinty'. He belonged to the Uí Ímair kindred. ;928 *Viking massacre of native Irish in

Dunmore Caves Dunmore Cave () is a limestone solutional cave in Ballyfoyle, County Kilkenny, Ireland. It is formed in Lower Carboniferous (Viséan) limestone of the Clogrenan Formation. It is a show cave open to the public, particularly well known for its r ...

County Kilkenny County Kilkenny ( gle, Contae Chill Chainnigh) is a county in Ireland. It is in the province of Leinster and is part of the South-East Region. It is named after the city of Kilkenny. Kilkenny County Council is the local authority for the cou ...

930s

;936 * Death of

, 32nd King of

940s

;944 *Death of Donnchad Donn mac Flainn, King of Mide; he is succeeded by Oengus mac Donnchada.

950s

;956 *Death of Congalach Cnogba, High King of Ireland, of the Síl nÁedo Sláine, part of the Southern Uí Néill. Domnall ua Néill becomes overking of the Uí Néill and reigns until his death in 980.

960s

;960 *

Gormflaith (modern spelling: or ) is an Irish language female given name meaning "blue princess" or "illustrious princess". is also a Gaelic mythological personification of Ireland. The word ' is a compound of the Irish words ' ("blue") and ' ("soverei ...

was born in Naas,

County Kildare County Kildare ( ga, Contae Chill Dara) is a county in Ireland. It is in the province of Leinster and is part of the Eastern and Midland Region. It is named after the town of Kildare. Kildare County Council is the local authority for the county, ...

. She was the daughter of Murchad mac Find, King of Leinster. She was also the mother of King Sigtrygg Silkbeard of Dublin. *Death of

Murchadh mac Aodha Murchadh mac Aodha (died 960) was 33rd King of Uí Maine. Reign and events Murchadh's reign is obscure. Some of the events recorded in Uí Maine, Connacht and Ireland during his lifetime include: * ''940.Cluain-mic-Nois (Clonmacnoise) and Cill ...

, 33rd King of

. ;964 * Mathgamain mac Cennetig, leader of the

Dál gCais The Dalcassians ( ga, Dál gCais ) are a Gaelic Irish clan, generally accepted by contemporary scholarship as being a branch of the Déisi Muman, that became very powerful in Ireland during the 10th century. Their genealogies claimed descent fr ...

from east

Clare Clare may refer to: Places Antarctica * Clare Range, a mountain range in Victoria Land Australia * Clare, South Australia, a town in the Clare Valley * Clare Valley, South Australia Canada * Clare (electoral district), an electoral district * Cl ...

, captures Cashel from the Eóganachta. ;968 *

Battle of Sulcoit The Battle of Sulcoit was fought in the year 968 between the Irish of the Dál gCais, led by Brian Boru, and the Vikings of Limerick, led by Ivar of Limerick. It was a victory for the Dál gCais and marked the end of Norse expansion in Ireland ...

where Brian Boru and Mathgamain defeat Ivar of Limerick.

970s

;970 *A hoard of 43 silver and bronze items was left in a rocky cleft deep in

near

Kilkenny Kilkenny (). is a city in County Kilkenny, Ireland. It is located in the South-East Region and in the province of Leinster. It is built on both banks of the River Nore. The 2016 census gave the total population of Kilkenny as 26,512. Kilken ...

. It consisted of silver, ingots and conical buttons woven from fine silver and was discovered in 1999. ;976 *Mathgamain, leader of the Dál gCais from east Clare, is killed. *Death of Muirchertach mac Mael Sechnaill, King of Mide. ;977 *

Brian Bóruma Brian Boru ( mga, Brian Bóruma mac Cennétig; modern ga, Brian Bóramha; 23 April 1014) was an Irish king who ended the domination of the High King of Ireland, High Kingship of Ireland by the Uí Néill and probably ended Viking invasion/domi ...

has Ivar of Limerick killed. ;977/8 *Brian Bóruma defeats the last independent Norse of Limerick in the Battle of Cathair Cuan. ;978 *Brian Bóruma defeats Máel Muad mac Brain in the

Battle of Belach Lechta The Battle of Belach Lechta or Bealach Leachta was a major battle fought in Munster in 978 between Máel Muad mac Brain, King of Munster, and Brian Bóruma. In the battle, the king was killed and Bóruma took over the role as the ''de facto'' ...

and becomes King of Munster