Events from the 9th century in Ireland .
800s
802
Death of Muiredach mac Domnaill, King of Mide . He is succeeded by Diarmait mac Donnchado.
803
804
806
Viking raid on Iona Abbey in which 68 people, the entire population of the abbey, are massacred.
807
810s
812
815
819
Conchobar mac Donnchada or Conchobar mac Donnchado is High King of Ireland with opposition (rí Érenn co fressabra ).
820s
820
822
830s
832
A Viking fleet of about 120 ships under Turgesius invades kingdoms on Ireland’s northern and eastern coasts.[ 5]
Clondalkin was sacked by Vikings from Denmark and the monastery was burned to the ground.
833
Death of Conchobar mac Donnchada, King of Mide and High King of Ireland with opposition.[ 6]
836
Viking raids penetrate deep inland.[ 4]
837
838 - 841
A small Viking fleet enters the River Liffey in eastern Ireland, probably led by the chieftain Saxolb (Soxulfr) who is killed later this year. The Vikings overwinter on Lough Neagh in 840[ 1] and set up a base, which the Irish call longphorts and which will eventually become Dublin .[ 2]
839
Thorgest (in Latin Turgesius ) is the first Viking to attempt creation of an Irish kingdom. He sails up the Shannon and the Bann to Armagh where he forges a realm spanning Ulster , Connacht and Meath .
840s
840
841
842
843
Death of Mael Ruanaid mac Dunnchado, King of Mide since 833.
845
846
Máel Sechnaill becomes overking of the Uí Néill , reigning until his death in 862.[ 4]
847
Death of Feidlimid mac Cremthanin, King of Munster, who has reigned since 820.[ 4]
847 or 848
Birth of Flann Sinna (d. 916), son of Máel Sechnaill I of Clann Cholmáin , a branch of the southern Uí Néill. He is King of Mide from 877.
848
Death of Fínsnechta mac Tommaltaig , King of Connacht .
Viking army defeated by Máel Sechnaill, High King of Ireland, near modern Skreen , County Sligo .
Viking army defeated by Tigernach mac Fócartai , King of Lagore , somewhere in modern County Sligo
Viking army defeated by Ólchobar mac Cináeda , King of Munster, and Lorcán mac Cellaig , King of Leinster , near modern Castledermot , County Kildare . The Viking leader Tomrair is killed; he is called jarl and deputy of the king of Laithlind .
Viking army defeated near Cashel by Ólchobar mac Cináeda.
Vikings at Cork ; besieged by Ólchobar mac Cináeda.
The Annales Bertiniani report the arrival of Irish envoys at the court of Frankish Emperor Charles the Bald . They bring gifts from the "king of the Irish" and announced an Irish victory over Vikings. The Irish annals record several defeats for Viking armies; which of these is meant is unclear. The identity of the "king of the Irish" is no more certain, but Ólchobar mac Cináeda may be intended rather than Máel Sechnaill.
Sedulius Scottus arrives at Liège , perhaps having been a member of the embassy to Charles the Bald .
850s
851
Máel Sechnaill mac Máele Ruanaid secures the submission of the King of Ulaid .[ 7]
Cináed mac Conaing is drowned on the orders of Máel Sechnaill and Tigernach mac Fócartai.[ 8]
853
Amlaíb , "son of the king of Laithlind ", arrives in Ireland and collects tribute from the Vikings and the Irish.[ 9]
860s
860 or 862
Death of Mael Sechnaill I, overking of the Uí Néill, who has reigned since 846.[ 4]
864
Death of Lorcan mac Cathail, King of Mide since 862.
866
870s
874
875
877
879
880s
880
882
883
885
888
890s
895
896
Notes
^ a b c d e f Foster, R. F. (1989). The Oxford Illustrated History of Ireland . Oxford University Press. ISBN 0198229704 .
^ a b c d e Mac Annaidh, Séamas, ed. (2001). Illustrated Dictionary of Irish History . Dublin: Gill & Macmillan. ISBN 9780717135363 .
^ Sawyer, Peter (2001). The Oxford Illustrated History of the Vikings . ISBN 9780192854346 .
^ a b c d e f Duffy, Seán (2005). The Concise History of Ireland . Dublin: Gill & Macmillan. ISBN 9780717138104 .
^ McGee, Thomas D'Arcy. A Popular History of Ireland . Archived from the original on 2007-09-29.
^ Moody ; Martin; Byrne, ed. Maps, Genealogies, Lists . p. 192, 193, n. 26.
^ a b c d e Moody, T. W.; Martin, F. X., eds. (1967). The Course of Irish History . Cork: Mercier Press. pp. 59, 95.
^ Byrne, Francis John . Irish Kings and High Kings . p. 263.
^ Annals of Ulster .
^ Lalor, Brian, ed. (2003). The Encyclopaedia of Ireland . Dublin: Gill & Macmillan. p. 9. ISBN 0-7171-3000-2 .