Olaf Guthfrithson
King of Dublin
Reign	934–939
Predecessor	Gofraid ua Ímair
Successor	Blácaire mac Gofraid
King of Northumbria
Reign	939–941
Predecessor	Æthelstan (as King of the English)
Successor	Olaf Cuaran
Died	941
Burial	Auldhame,Scotland(possibly)
Issue	Cammán Gofraid Ímar
Dynasty	Uí Ímair
Father	Gofraid ua Ímair

Olaf Guthfrithson orAnlaf Guthfrithson (Old Norse:Óláfr Guðrøðsson[ˈoːˌlɑːvz̠ˈɡuðˌrøðsˌson];Old English:Ánláf;Old Irish:Amlaíb mac Gofraid; died 941) was a Hiberno-Scandinavian (Irish-Viking)^{[nb 1]} leader who ruledDublin andViking Northumbria in the 10th century. He was the son ofGofraid ua Ímair and great-grandson ofÍmar, making him one of theUí Ímair. Olaf succeeded his father asKing of Dublin in 934 and succeeded in establishing dominance over the Vikings ofLimerick when he captured their king,Amlaíb Cenncairech, in 937. That same year he allied withConstantine II of Scotland in an attempt to reclaim theKingdom of Northumbria which his father had ruled briefly in 927. The forces of Olaf and Constantine were defeated by the English led byÆthelstan at theBattle of Brunanburh in 937.

Olaf returned to Ireland in 938 but after Æthelstan's death the following year Olaf left forYork where he was quickly able to establish himself as king, with his brotherBlácaire mac Gofraid being left to rule in Dublin. Olaf and Æthelstan's successorEdmund met in 939 atLeicester where they came to an agreement regarding the division of England between them. This agreement proved short-lived, however, and within a few years Vikings had occupied theFive Boroughs ofDerby,Leicester,Lincoln,Nottingham andStamford. Olaf died in 941 and was succeeded in Northumbria by his cousinOlaf Cuaran. At the time of his death, theIrish annals title him "king of Danes" and "king of theFair Foreigners and the Dark Foreigners".

Olaf first conclusively appears in contemporary records in 933 when the annals describe him plunderingArmagh on 10 November.^[2] He is then recorded as allying with Matudán mac Áeda,overking of Ulaid and raiding as far asSliabh Beagh, where they were met by an army led byMuirchertach mac Néill ofAilech, and lost 240 men in the ensuing battle along with much of their plunder.^{[nb 2]} An earlier reference to a "son of Gofraid" who plundered the monastery atKildare in 928 might refer to Olaf but no name is given.^[6] Olaf's fatherGofraid ua Ímair,King of Dublin, died in 934 and Olaf succeeded him as king.^[2][7] The following year Olaf carried out a raid at Lagore crannog inCounty Meath, and then looted the burial chamber atKnowth the following week.^[6][2]

Olaf is described as "Lord of the Foreigners" by theAnnals of the Four Masters in 937,^[8] at which time he went toLough Ree and capturedAmlaíb Cenncairech,King of Limerick, and his troops after breaking their boats.^[6][2] This conflict can be ascribed to rivalry between the competing Viking settlements of Dublin and Limerick, with this event marking victory for Dublin. This period is considered to be the high-point of Viking influence in Ireland.^[9] Having secured his position in Ireland, Olaf turned his attention to England andNorthumbria, which had once been ruled by Olaf's father and had been conquered in 927 byÆthelstan of England.^[7] Olaf allied withConstantine II of Scotland, whose kingdom had been invaded by Æthelstan in 934, and in 937, the same year as the victory over Limerick, Olaf and the Vikings of Dublin left for England.^[10]

The allied forces of Olaf and Constantine met the forces of Æthelstan at theBattle of Brunanburh, at a site which is the subject of much debate, although current scholarly consensus identifies the site asBromborough inCheshire.^[2][11] Olaf and Constantine commanded the Viking troops while Æthelstan alongside his brotherEdmund led the English troops into the battle. Contemporary accounts indicate both sides suffered many casualties but the result was a decisive English victory. Olaf and Constantine survived the battle and returned to Ireland and Scotland respectively, but one of Constantine's sons died.^[10] The battle is well-attested, with references in Irish chronicles, and apoetic telling of the battle in theAnglo-Saxon Chronicle.^[12][13] The numerous references to it in various chronicles throughout the British Isles testify to its perceived importance at the time.^[10]

The annals record Olaf's return to Ireland in 938 as well as a raid he carried out that year onKilcullen in modern-dayCounty Kildare, where he is said to have taken a thousand prisoners.^[6] Æthelstan died in October 939 and very soon afterwards Olaf left for York where he was able to quickly establish himself asking of Northumbria. Olaf was joined in England by his cousinOlaf Cuaran, and Olaf's brotherBlácaire was left to rule in Dublin while he was away.^[14][15]Symeon of Durham'sHistoria Regum records that Olaf and the new English king Edmund met at Leicester in 939 and came to an agreement on dividing England between the two of them.^[16] This peace was short-lived and within a few years of the agreement the Vikings had seized theFive Boroughs ofDerby,Leicester,Lincoln,Nottingham andStamford.^{[nb 3][17]}In 941 theChronicle of Melrose records that Olaf raided an ancientAnglian church atTyninghame in what is now theEast Lothian and at the time was a part of Northumbria.^[18][19] This attack may have been more than just a raid, and may have been intended to secure a route through Scotland upon which communication between York and Dublin was reliant.^[20] Olaf died in 941 and he was succeeded in Northumbria by Olaf Cuaran.^[15] In recording his death, the annals title him "king of Danes" (Chronicon Scotorum) and "king of theFair Foreigners and the Dark Foreigners" (Annals of Clonmacnoise).^[21][22]

In 2005, a skeleton was excavated in an archaeological dig atAuldhame,East Lothian. Grave goods including a belt similar to others known to have been worn in Viking-age Ireland indicate that the skeleton belonged to a high-status individual. The presence of such goods, and the age of the skeleton, has led to speculation among historians and archaeologists that the remains could be those of Olaf.^[23] Olaf is known to have conducted raids on Auldhame and Tyninghame shortly before his death in 941.^[24] Auldhame and Tyninghame were two of several local churches dedicated toSaint Baldred. According toAlex Woolf, although the skeleton cannot be definitively identified with Olaf, the date and nature of the burial make it very likely the deceased individual died as a consequence of Olaf's attacks in the area in 941. Woolf has also suggested that "there is a strong likelihood that the king’s followers hoped that by burying him in the saint’s cemetery he might have benefitted from some sort of post-mortem penance".^[23]

Olaf's father is identifiable as Gofraid, who was king of Dublin between 920 and 934, and also briefly ruled Northumbria in 927.^[25][26] Gofraid was a grandson ofÍmar but no patronymic is given in the original sources. This may be because he was a child of a son of Ímar who never ruled Dublin, or he was a child of a daughter of Ímar, which in either case would mean his legitimacy to rule in the eyes of his contemporaries was dependent on the identity of his grandfather, not his parents.^[27] Ímar, possibly identical toIvar the Boneless, was the founder of theUí Ímair and was one of the earliest kings of Dublin in the mid-ninth century.^[28]

Three other individuals are identifiable as sons of Gofraid; Albann, Blácaire and Ragnall.^[25] Albann was killed in battle against Muirchertach mac Néill in 926.^[29] Blácaire ruled Dublin from 939 onwards, andRagnall mac Gofraid ruled Northumbria in 943 and 944, probably along with his cousin Olaf Cuaran, until they were driven out byEdmund I of England.^[14][30]John of Worcester, writing in the twelfth century, claimed that Olaf had married a daughter of Constantine II of Scotland prior to 937, but this evidence is considered unreliable.^[31] The thirteenth century chroniclerRoger of Wendover wrote that Olaf married Aldgyth, the daughter of a Northumbrian earl called Orm as a consequence of the agreement at Leicester between Olaf and King Edmund.^[32]

An individual namedCammán mac Amlaíb is identifiable as a son of Olaf. TheAnnals of Ulster record he was defeated at a place called Dub in 960. Cammán may have been one of the meic Amlaíb (sons of Olaf) who theAnnals of the Four Masters mention in 962.^{[33][34][35][36]} According to this account the sons of Olaf and the Ladgmanns (lawmen) came to Ireland and plunderedConaille Muirtheimne andHowth. Afterward the lawmen went to Munster to avenge their brother Oin. They continued the plunder there and were defeated by the Irish inUí Liatháin where 365 of them died. In the same year an unnamed son of Olaf led a raid fromIreland's Eye onAnglesey and Britain.^[36][35] Cammán may be identical to Sitriuc Cam, an individual who in 962 made a naval attack on Uí Cholgain, but was forced to flee back to ships after a force of Dubliners and Leinstermen overtook him and slaughtered some of his men.^[37] An individual named Gofraid mac Amlaíb recorded by the annals as dying in 963 may have been a son of Olaf or he may have been a son ofOlaf Cuaran.^[38] TheAnnals of Clonmacnoise list an Ímar, a "son of the king", among the dead at Brunanburh who might be a son of Olaf, although the origin of this list is uncertain.^[39][40]

• "Annals of the Four Masters".Corpus of Electronic Texts (16 December 2013 ed.).University College Cork. 2013. Retrieved23 November 2014.
• "The Annals of Ulster".Corpus of Electronic Texts (15 August 2012 ed.).University College Cork. 2012. Retrieved23 November 2014.
• "Chronicon Scotorum".Corpus of Electronic Texts (24 March 2010 ed.).University College Cork. 2010. Retrieved26 November 2014.
• Murphy, D, ed. (1896).The Annals of Clonmacnoise. Dublin:Royal Society of Antiquaries of Ireland. Accessed viaInternet Archive.
• Stevenson, Joseph, ed. (1853).The Church Historians of England. Vol. 4, Part 1. London: Seeleys. Accessed viaInternet Archive.
• Thorpe, B, ed. (1861).The Anglo-Saxon Chronicle. Rerum Britannicarum Medii Ævi Scriptores. Vol. 2. London: Longman, Green, Longman, and Roberts. Accessed viaInternet Archive.

• Bartlett, Thomas; Jeffrey, Keith (9 October 1997).A Military History of Ireland. Cambridge University Press.ISBN 978-0-521-62989-8.
• Cannon, John (21 May 2009).A Dictionary of British History. OUP Oxford.ISBN 978-0-19-955037-1.
• Downham, Clare (2007).Viking Kings of Britain and Ireland: The Dynasty of Ívarr to A.D. 1014. Edinburgh:Dunedin Academic Press.ISBN 978-1-903765-89-0.
• Forte, Angelo; Oram, Richard D.; Pedersen, Frederik (5 May 2005).Viking Empires. Cambridge University Press.ISBN 978-0-521-82992-2.
• Harper-Bill, Christopher (1998).Proceedings of the Battle Conference in Dublin, 1997. Boydell & Brewer.ISBN 978-0-85115-573-9.
• Hart, Cyril (2004)."Sihtric Cáech (d. 927)".Oxford Dictionary of National Biography (online ed.). Oxford University Press.doi:10.1093/ref:odnb/25543. Retrieved6 January 2015. (Subscription,Wikipedia Library access orUK public library membership required.) Subscription orUK public library membership required.
• Hudson, Benjamin T. (2004)."Óláf Guthfrithson (d. 941)".Oxford Dictionary of National Biography (online ed.). Oxford University Press.doi:10.1093/ref:odnb/20670. Retrieved15 August 2015. (Subscription,Wikipedia Library access orUK public library membership required.) Subscription orUK public library membership required.
• Roffe, David (2012).The English and Their Legacy, 900-1200: Essays in Honour of Ann Williams. Boydell Press.ISBN 978-1-84383-794-7.
• Stenton, Frank M. (1971).Anglo-Saxon England (3rd ed.). OUP Oxford.ISBN 978-0-19-280139-5.

• Halloran, Kevin (December 2013). "Anlaf Guthfrithson at York: A Non-existent Kingship?".Northern History.50 (2). University of Leeds:180–185.doi:10.1179/0078172X13Z.00000000042.S2CID 154514458.
• Capener, D.H (2014)Brunanburh and the Routes to Dingesmere, Countyvise

• CELT: Corpus of Electronic Texts atUniversity College Cork. TheCorpus of Electronic Texts includes theAnnals of Ulster andthe Four Masters, theChronicon Scotorum and theBook of Leinster as well as Genealogies, and various Saints' Lives. Most are translated into English, or translations are in progress.

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