Einarr, also known as Torf-Einarr, left a significant legacy by establishing a dynasty that ruled the Orkney Islands until 1470. This information is supported by the Wikipedia article on Torf-Einarr, which states, "Despite his apparent physical shortcomings, as well as his low-born mother, Einarr established a dynasty which ruled the Orkney islands until 1470" source. This legacy is a testament to Einarr's influence and the lasting impact of his rule in the region.