Sigurd is a legendary hero of traditional Norse religion, as well as the central character in an Icelandic saga. The earliest extant representations for his legend come in pictorial form from 7 runestones in Sweden, most notably the Ramsund carving (c. 1000) & the Gök Runestone (11th century). As Siegfried, he would become one of the heroes in the German epic poem Nibelungenlied, & in Richard Wagner's operas Siegfried & Götterdämmerung.
The ravens are shown intertwined in knotwork to symbolize their interconnectedness – not only to each other, but also to Odin, the physical world and the knowledge they seek. They are perched on a rune stone upon which is carved a sampling of Futhark (the Norse alphabet) and a depiction of Odin astride his eight-legged horse, Sleipnir.