On this Nordic island, marooned near the peak of the globe, the temperature can drop below -20 degrees. A sweater is a must. Toddlers, teens, and fishermen alike all wear the Icelandic wool sweater, a uniform that the nation of ice and snow embraces. They call it lopapeysa, a name that literally translates to “yarn sweater.” Unlike a basic yarn sweater, the Icelandic lopapeysa carries the distinctive yoke pattern, a wide decorative circle that fans out from the neck opening. Most importantly, its warmth is a gift from their beloved sheep.

You’d expect to find this iconic wool sweater spotlighted in a glass case in Reykjavik’s National Museum as part of a 19th-century exhibit, or perhaps captured in black-and-white historical photos, a cultural heirloom spun by the people of Viking blood.

But you’ll find no such thing. The sweater curiously first appeared on Icelanders in the 1950s with a murky origin story. Some say that Auður Laxness, the wife of Iceland’s Nobel laureate Halldór Laxness, returned from Greenland with a wool sweater and recreated one using Icelandic patterns and a book on Incan culture as her inspiration.

While the story of the very first Icelandic sweater remains a mystery, the lopapeysur were essentially born from a desire to return to hand-knitting after the rise of industrial production. Furthermore, Icelanders wanted to find a purpose for the abundance of wool from the gorgeous sheep of the island.

If you follow the 828-mile Ring Road that traces the island’s perimeter, you’ll see these sheep roaming the roads and farmlands, all direct descendants from those brought by the 9th century settlers. After hundreds of years in the sub-Arctic climate, isolated from the sheep of the Continent, the Icelandic sheep have retained coats that are exactly like their ancient forefathers. Their fleece form two distinct layers: the fluffy, insulating fibers closest to their bodies, which are known as þel, and the coarse, water-repellent fibers called tog.

Icelanders mix them together to create lopi, a wool that’s warm and light, but also durable and resistant to the elements. Thanks to the dual textures of the lopi, Icelanders can step out into the harsh winter air in their wool sweaters with no jacket – they can even wear it out on the North Atlantic, and a splash of seawater poses no harm.

While some dye the wool, Icelandic farmers take pride in breeding their sheep in earthy shades of brown and grey, black and white — colors that commonly compose the design of the yoke. Farmers also hold deep emotional bonds with their sheep, which have ensured Icelanders’ survival since settlement days. To understand this bond, watch the 2015 drama Rams, which captures this intimate relationship through the story of two brothers who must exterminate their herds after a case of scrapie breaks out (the film also features plenty of beautifully crafted lopapeysur).

Despite being a relatively new addition to Icelanders’ wardrobes, the lopapeysa has become a symbol of national identity and is now as Icelandic as skyr (a yogurt-type dairy product) or the sagas of the medieval settlers. In the words of Icelandic writer Árni Árnason, the lopapeysa “resembles the country’s rugged nature and reminds us of the history of farming and fishing when it provided its wearer with a vital shield from the disastrous weather one can encounter in the wild.” When Icelanders wear these sweaters, they’re drawing close the craftsmanship of their people, as well as old cultural ties to their sheep.

Icelanders are also keen on sharing their lopapeysur with the world. In the capital, you’ll find countless sweaters, ranging from the traditional yoke with naturally-colored yarn to brightly-colored sweaters adorned with zippers, hoods, or fur.

Árnason thinks that lopapeysa “appeals greatly to the disillusioned and globalised 21st Century traveller.” In a time where clothes that celebrate authentic craftsmanship and tradition (even “invented culture” as is the case with the lopapeysa) are a bit harder to find, he makes a point. But if you dig a little deeper and know where to look, this great work can still be found.

Delve deeper into the fascinating world of wool and fashion by reading our article, “The Hidden Powers of a Sheep” in Craftsmanship Magazine.