If the Vikings had seen pictures of Santa Claus cruising the skies in a sleigh pulled by reindeer, they probably would have assumed he was catching a ride with Thor, the Norse god of thunder.
According to Viking traditions, which carry over into modern Scandinavian Jul - or Yule - celebrations, Thor's personal transport was a flying wagon pulled by a team of horned goats.
"The idea of St Nicholas got very much mixed in with Thor's transport when it comes to the sled with flying reindeer," said Helge Soerheim of the Archaeological Museum in Stavanger.
Some say the idea of Father Christmas or Santa bringing gifts stems from Norse mythology, too, since the most powerful of the Viking gods, Odin, was credited with doing the exact same thing, according to the Norwegian research magazine Forskning.
Even though Christianity came to Scandinavia a millennium ago, modern celebrations of Christmas hark back to the pagan winter feast of Jul, which comes from the Norse word `Jol', meaning fun and party.
Today, Jul marks the birth of Jesus and is part of the Christian tradition, but it is still referred to by its ancient name.
"Everything about it is ancient Jul. The name, the concept, the lights in the darkness, the good food, everything but the Christianity part," said Wenche Brun, who works with the Viking Museum on northern Norway's Lofoten Islands.
Ancient Jul was celebrated on December 21, then believed to be the longest night of the year. It was easy to shift to the Christian celebration that takes place on December 24.
Today, Scandinavians are overwhelmingly Christian. In Norway, for example, 86 per cent of the 4.6 million people are registered members of the state Lutheran Church of Norway.
Modern Scandinavians would say they celebrate Yule, while the Vikings "drank Jul".
And a key part of "drinking Jul" - today as in the year 1000 - is brewing special Christmas beers.
In Norway alone there are more than 50 kinds of Juleoel, or Christmas beers, ranging in strength from 4.5 to 9.9 per cent alcohol, brewed just before the holidays each year. They are darker and more flavourful than regular beers.
In Viking times, Helge Soerheim said, people thought drinking themselves into a stupor on holiday beer and other alcoholic beverages would create a euphoric connection with supernatural forces. And failure to get drunk at a Viking feast was an insult to the host, implying that his alcohol wasn't good enough.
Because modern Jul is generally a family affair, today's Scandinavians are more moderate in their "drinking Jul".
But the old Viking toast - "to a good new year and peace" - still echoes in the modern Christmas wishes of the North, Soerheim said.
Even after Christianity made inroads, brewing Jul-time beer remained a serious matter. In medieval times, every farmer was required to brew Christmas beer or risk fines and worse.
"Everyone had to make two batches of Christmas beer a year, one for themselves and one for guests, or be fined three riskdollars," Olaug Flakne, 31, Norway's only female brew master, said, referring to the currency of that day.
"If they did not do it for three years in a row, their farms were taken away, and, if they were also not Christian, they were expelled from the country," she said at the brewery on the outskirts of Oslo.
In old times, Norwegians used whatever was at hand, from juniper berries to tobacco, to flavour the beers.
But under the Beer Purity Act of 1516, which was repealed in 1994 but is still heeded by Norwegian brewers today, only malt, hops, yeast and water can go into beer.
Ringnes, Flakne's employer and Norway's largest brewery, alone makes 3.3 million litres (nearly 870,000 gallons) of Christmas beer, in 18 varieties.
Not everyone is happy about the connection between Christmas and the brewing of beer. In the 1960s, the Christian Sobriety Society demanded that the name Juleoel, or Jul Beer, be banned.
The national brewers' association, however, successfully countered that Jul has nothing to do with Christmas or Christianity but stems from Viking times.
Other Christmas traditions appear to have been passed down from the Vikings. Many believe the "Julenek," a sheaf of grain Norwegians place outside for the birds each Christmas, stems from the Vikings' Jul offerings to their gods. Others say it may have a later origin, such as sharing Christmas bounty with all creatures.