Tom Jerso is a fairly fearsome sight to see lunging at you with a yard-long steel sword. He is not only large, he is impressively decorated. Jerso is wearing these clothes: brown leather boots tied with strips of leather thong, a long brown tunic made of coarse cloth, and a brown woolen kirtle—the knee-length sleeved shirt that tenth-century Norsemen used to pull over their heads. His sheepskin-lined scabbard is brown, too. He looks like a GIANT Advil.

Here at the National Museum of Denmark in Copenhagen, Jerso and his fellow Viking re-enactors sing ancient ballads, exchange oaths and rampage (politely), weapons glinting. With an action well-honed by experience, and a hand well protected by glove, another Viking—this one calling himself Ragnar Lodbrok (Hairy Breeches)—shoulders a broadax. His cloak, fastened by an iron brooch, is cornflower blue; his leggings are tucked into peri­winkle pantaloons, craftily ripped at the knees. He looks like an Aleve.

More pain inflictors than relievers, these Danes are on hand for the final day of “Viking,” a major exhibition that reopens at the British Museum on March 6 and runs through June 22 before moving to Berlin in September. “Over the last few decades much new evidence has come out that has changed our perception of Viking culture,” says Anne Pedersen, a curator of the show.

Since 1980, the benchmark exhibitions on Vikings have keyed on their European homelands and their colonial incursion in the Atlantic islands (British Museum, 1980); Russia and the East (in Paris, 1992); and, to commemorate the 1,000-year anniversary of the Vikings’ arrival in North America, the expansion to Greenland and Vinland (Smithsonian Museum of Natural History, 2000). By focusing on the violence of Viking society, the new exhibition revives the traditional image of Vikings as Dark Age bad boys—Pillage People, if you will, who bullied Britain and France, and even made it as far as Baghdad.

The showstopper is a Viking warship whose surviving timbers are on display for the first time. One hundred twenty-one feet from prow to stern, the boat was capable of carrying 100 troops at speed. It was discovered by chance in 1996, about a lance throw from the Viking Ship Museum in Roskilde, Denmark. “Warships of this kind are comparatively rare finds, and this is the largest known,” says Neil Price, a professor of archaeology at the University of Aberdeen in Scotland. “It serves as a symbol of the Viking raids, and also an indicator of the sophistication of the societies that launched them.”

Lithe, narrow longships, praised in sagas, allowed the Vikings to enter countries through rivers, and it’s this access that enabled them to make lightning attacks on unsuspecting coastal hamlets and plunder parts of three continents. With sailing ships and their capability to beat to windward, the whole world was brought within reach. No wonder British Museum director Neil MacGregor has said the exhibition’s centerpiece is an “11th-century weapon of mass destruction.”

They journeyed boldly;

Went far for gold,

Fed the eagle

Out in the east,

And died in the south

In Saracenland

—Gripsholm Rune-Stone (c. 1050)

Vikings were a Germanic bunch made up of Danes, Swedes, Norwegians and Gauls who, during the late eighth century, swept south across the Baltic Sea in search of land, slaves, gold and silver. They were pagans in a Christian Europe, replete with gruesome rituals. In their world, power and influence were tribal, and rule was sustained though clan, trade and military might.

In the Old Norse language, Viking may have meant “men of the bays”— sheltered coves were where they lay in ambush of merchant ships. Price likens them to 17th- and 18-century pirates—an idea that could radically change how we see the beginnings of the great raids, and how they reflect what was happening in Scandinavia at the time.