Sveinbjörn was born in 1924 in Grafardalur, but from the age of 20 farmed the land at Dragháls in Borgarfjörđur, in 1965 he married Svanfríđur Hagvaag (divorced). They had two sons.
He is perhaps best known as the Allsherjargođi (supreme head) of the official Icelandic Ásatráarfélagiđ (or Ásatrú-sect), the sect devoted to the survival of the heathen religion of pre-christian Iceland. Amongst others things, Sveinbjörn got Ásatrúarfélagiđ officially recognised as a religious body in 1972 after a long battle with the Ministry of Justice & Ecclesiastical Affairs, the first non-christian group to receive such rights, and served as the Allsherjargođi from the beginning.
Apart from the farming the main bulk of Sveinbjörn's work lay in the Rímur and other poetry with the older Germanic form and metre.
Rímur is a kind of "sung Poetry" and is closely related to the epic singing traditions of early Europe, unlike other conventional European vocal music the Rímur where not affected by later and/or imported musical characteristics. The Rímur singing reminds one of the vocal chanting from the middle east, but the forms are not related and unlike the Arabic counterpart the "sung poetry" of Iceland has no tonal scale but is a free-form wave of sound. Still it's a strict form of expression with stability in the volume, pitch, tempo and length of syllables.
Using the Rímur singing as a basis Sveinbjörn almost single-handed recreated the art of epic singing of the Eddic metre/forms, the forms used by the Scandinavian and English poets of pre Christian times, that created such masterpieces as Völuspá and Beowulf (Bjólfskviđa). The modern reader of such poetry tends to forget that the Eddic poetry, Frankish lays, Beowulf and other old Germanic poetry was meant to be recited, not read.
As the Nordic intelligentsia had dismissed the singing of Rímur and epic lays to be "the primitive groans of farmers", and the older forms of poetry where thought to be "outdated, primitive and restrictive" (in other words, hill-billy "art", not to be taken seriously) Sveinbjörn turned to the younger generation of listeners with his offerings.
Thus, in the late seventies/early eighties he often performed with the various New Wave, Industrial and Punk-rock artists, groups like Psychic TV Ţeyr (members later in Psychic TV, Killing Joke, Kukl, Sugarcubes & Frostbite) and Purkur Pilnikk (whose members later started Kukl & the Sugarcubes), a move which earned him the respect and admiration of the younger music fans and the disrespect, hatred even, of self-appointed "cultural moguls" and poetry/literature scholars.
He kept these close ties to the rock/industrial community and his records where published by independent rock labels, rather than the classical or early music specialist labels that you would have expected to find his work on.
Apart from rekindling the interest in traditional forms of poetry and poetry singing amongst the "indy rock" musicians in Europe, he occasionally had other dealings with them, he conducted the marriage ceremony of Genesis Porridge and his beloved (?) Paula, and the rate of Industrial/noise artists amongst the members of