Perhaps the most striking of Viking achievements was their state-of-the-art shipbuilding technology, which allowed them to travel greater distances than anyone before them. Their signature longboats—sleek wooden vessels with shallow hulls and rows of oars along the side—were faster, lighter, more flexible and more easily maneuverable than other ships of the time.

But the Vikings’ exploring prowess also owed a great deal to their skill as navigators. They relied on simple but sophisticated tools like the sun compass, which utilized calcite crystals known as “sunstones” to identify the position of the sun even after sunset or on overcast days. Such innovations gave Vikings a distinct advantage when traveling long distances to foreign lands. In their heyday, Vikings were active on four continents simultaneously, making them the first true global citizens.

In the centuries after their first raid on English soil in A.D. 793, Vikings made a historic series of attacks, waged wars and formed settlements in the British islands, leaving a permanent impact on the land, culture and language. As the Vikings interacted with their English neighbors, first through farming and trading activities and later through intermarriage, the two languages (Old Norse and Old English) mixed as well. This process is evident in place names such as Grimsby, Thornby and Derby (the suffix -by was the Scandinavian word for “homestead” or “village”), or Lothwaite (-thwaite meaning “meadow” or “piece of land”). “Give,” “window” and “dream,” among other common English words, also derived their modern meanings from Viking influence. In another famous example, the word “berserk” comes from the Old Norse berserker, meaning “bear shirt” or “bearskin.” These Viking warriors worshipped Odin, the god of war, and whipped themselves into a frenzied state before and during battle.

We owe the capital of the Emerald Isle to the Vikings, who founded the first recorded settlement on the south bank of the River Liffey in A.D. 841. Named Dubh Linn (“Black Pool”) after the lake where the ancient Norsemen moored their boats, the Viking settlement centered around a timber-earthen fort called a longphort. Built at what is now the heart of modern-day Dublin, it became the hub of one of Europe’s largest slave markets. The Vikings kept firm control of Dublin for nearly three centuries, until the Irish High King Brian Boru defeated them in the Battle of Clontarf in 1014. Unlike in England, Vikings left few Norse place names in Ireland or words in the Irish language, but they made their mark there nonetheless. In addition to Dublin, the Irish cities of Wexford, Waterford, Cork and Limerick also began as Viking settlements.

Though the oldest known skis, dating to between 8000 and 7000 B.C., were discovered in Russia, and the first written reference to skiing comes from China’s Han Dynasty (206 B.C.-A.D. 220), we have the Vikings to thank for inaugurating the Western tradition of skiing. Even the word “ski” comes from the Old Norse “skío.” Ancient Norsemen skied across their snowy homelands for both recreation and transportation purposes, and the Norse goddess Skaoi and god Ullr were often depicted on skis or snowshoes.

Though their enemies considered them unkempt barbarians, Vikings actually bathed more frequently than other Europeans of the day, taking a dip at least once a week—preferably in a hot spring. Bristled combs, often made from the antlers of red deer or other animals they killed, are one of the objects most commonly found in Viking graves. In fact, though comb-like devices existed in other cultures around the world, Vikings are often given credit for inventing the comb as the Western world knows it today. Tweezers, razors and ear spoons (for scooping out wax) are among the other grooming objects turned up in excavations of Viking burial sites, proving that even longhaired, bearded Viking warriors took their personal grooming very seriously.

Aside from archaeological evidence, one of modern historians’ primary sources for information about Viking life comes from a somewhat dubious but endlessly entertaining source. The Icelandic sagas, written by unknown authors in the 12th, 13th and 14th centuries, chronicle life in the Viking Age around the year A.D. 1000, when the ancient Norsemen abandoned their pagan gods and converted to Christianity. Victorian-era scholars accepted the sagas, with their graphic depictions of the deeds of both powerful rulers and ordinary people, as fact. Today, most historians agree they are an unreliable—yet still valuable—source of information about the Vikings, laced with a hefty dose of mythology and fantasy. In any case, we can thank the Vikings and their exploits for providing fodder for one of the earliest forms of our favorite guilty pleasure: the soap opera.