Sichfrith orSigfrith (Old Norse:Sigfrøðr), also known asSichfrith Jarl, was a ninth-centuryNorse orNorse-GaelJarl who claimed the kingship ofDublin in 893, but it is unclear if he ever ruled. Later historians have linked him with two individuals of the same name. The first, aNorthumbrianViking who a led a fleet south and landed troops inWessex in 893, and the second, a King ofJórvík who reigned from 895 until around 899.

Sichfrith is mentioned by name only once in contemporaryIrish Annals:^[1]

A great dissension among the foreigners ofÁth Cliath, and they became dispersed, one section of them followingÍmar's son, and the other Sigfrith the jarl.^[2]

According toDownham, it is possible Sichfrith was able to claim the throne ofDublin by belonging to the same kin-group as the three sons ofÍmar who ruled Dublin consecutively from 873 until at least 893.^[3] Both Sichfrith and his rival to the kingship, Sitriuc mac Ímair, left Ireland in 893 to war inBritain. Sitriuc returned the following year but it is not clear if he or Sichfrith remained king.^[4]

A commander named Sichfrith led theNorthumbrian fleet againstWessex in 893.^[5] Though there is no way to know for sure if this Sichfrith and the one mentioned in the Irish Annals are the same, it is certainly plausible, and it is likely that there was contact between theViking kingdoms of Northumbria and Dublin during this period.^[6] Two competing theories have been put forward for Sichfrith's origins.Smyth has proposed Sichfrith was a Northumbrian who sailed to Dublin after his fleet landed troops in Wessex. According to this theory Sichfrith failed to take the city and caused the split noted by theAnnals of Ulster.^[7]Angus instead proposes that Sichfrith was a Dubliner who left forEngland after he failed to take the throne.^[8] Smyth's explanation is considered more likely sinceÆthelweard in hisChronicon implies Sichfrith was a Northumbrian.^[5]

Coins bearing the nameSigfrøðr were found in theCuerdale Hoard, indicating a king of that name rulingJórvík until about 900, succeedingGuthfrith.^[9]Smyth and others have proposed that this Sigfrøðr is the same person as the Sichfrith mentioned in the Irish Annals and by Æthelweard.^[10] These coins are the only evidence for a king of Jórvík of that name.^[9]Ashley gives the approximate dates of 895 until 899 for his reign.^[11]

• "The Annals of Ulster".Corpus of Electronic Texts (15 August 2012 ed.).University College Cork. 2012. Retrieved23 November 2014.
• Æthelweard (1961). Campbell, Alistair (ed.).Chronicon. London: Thomas Nelson.

• Ashley, Mike (7 June 2012).The Mammoth Book of British Kings and Queens. Little, Brown Book Group.ISBN 978-1-4721-0113-6.
• 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.
• Smyth, Alfred P. (1975).Scandinavian York and Dublin: the history and archaeology of two related Viking kingdoms. Templekieran Press.
• Angus, W. S.Christianity as a Political Force in Northumbria in the Danish and Norse Periods. inSmall, Alan, ed. (1965).The Fourth Viking Congress: York, August, 1961. Oliver and Boyd, for the University of Aberdeen.

• 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.

• 9th-century Irish monarchs
• Monarchs of Dublin

• Articles with short description
• Short description matches Wikidata
• Use dmy dates from April 2022
• Articles containing Old Norse-language text
• Year of birth unknown