Ragnvald, Earl of Møre

Rognvald Eysteinsson (fl. 865) was the founding Jarl (or Earl) of Møre in Norway, and a close relative and ally of Harald Fairhair, the earliest known King of Norway. In the Norse language he is known as Rognvaldr Eysteinsson and in modern Norwegian as Ragnvald Mørejarl. He is sometimes referred to with bynames that may be translated into modern English as "Rognvald the Wise" or "Rognvald the Powerful".

The earliest available sources regarding Rognvald are mutually contradictory and were complied long after he died. The best known are the Norse Sagas, although modern scholars highlight many inconsistencies and improbable claims regarding Rognvald in the sagas, and believe that they must be treated with caution: The texts of the sagas were compiled three centuries after the events described and their accuracy in regard to Rognvald's life and historical significance is now questioned. Hence some scholars instead emphasise other accounts, closer to the historical period in question, such as Irish and Scottish sources.

While Rognvald does appear to have had some kind of role in the founding of the Norse Earldom of Orkney, most historians now doubt claims in the Sagas that Rognvald led one particular "great voyage" – a Norwegian expedition that attacked rebel vikings, who had been raiding Norway from bases on Orkney and Shetland, before raiding the Scottish mainland, Ireland and the Isle of Man. It is now generally believed that any such expedition would have occurred after Rognvald's lifetime. A modern authority on Orcadian history, William P. L. Thomson, comments that the story of the "great voyage is so thoroughly ingrained in popular and scholarly history, both ancient and modern, that it comes as a bit of a shock to realise that it might not be true."

Modern scholars also highlight inconsistencies and improbable claims in the sagas' claims regarding: the relationship between Rognvald and Harald; the names and biographies of Rognvald's immediate family, and; the founding of the earldom of Møre.