Sirtyans are a mythical people, who once lived around the Nenets okrug, before they were replaced and assimilated by the migrating Nenets from the east. According to legend, they came from across the arctic to settle on Yamal.
They are described to be very short and with light eyes. They wore beautiful clothes with metal pendants. In general, they are described as great metallurgists and blacksmiths. Unlike the Nenets, they were mainly hunters, though legends also say they herded mammoths underground.
They apparently lived on sandy hills or underground, coming to the surface only at night. There were also cases of marriages and military clashes between Sirtyans and Nenets. The Sirtyans were said to come out and hide quickly, making fighting them very difficult.
There are a lot of myths about Sirtyans and their magical abilities. One story talks about 3 Sirtyan brothers and their sister who lived on the mountain Nad Jara Salja. The god of the underworld Nga shows up and demands the sister be married to him, when the brothers refuse...
...Nga causes a huge storm, making the mountain fall upside down, the brothers are left underneath, the sister remained on the surface. One day, a hero Mando Mjang arrives to helps the sister dig up her brothers. The elements obey the heroes and the Sirtyans become gods.
Many archeological finds have been connected to Sirtyans. One such is site is Buhta Nahodka, on the Yamal peninsula. A fort used to stand there, with many finds of archeological items, including jewelry of bronze, glass and amber.
Even medieval Arabic writings likely described the Sirtyans, living north of Wisu (Perm). The Bulgars traded swords to them which they used for hunting whales. And they live by a giant tree with a giant bird overlooking them. There's even a case of a Sirtyan man visiting Bulghar.
There are many theories regarding who were the Sirtyans and where did they come from. My theory is that they were a Finno-Ugric subgroup, most closely related to the Permians, hence why the light pigment and great metallurgy skills.