Jólasveinar first appear in the 17th century as the sons of
Grýla and Leppalúði, who had appeared in the 13th century,
and had a reputation for stealing and eating naughty children.

The Jólasveinar were counted as numbering either nine or thirteen,
but their names are at least 70.

Thirteen of the most commonly accepted names of the Jólasveinar are:

Stekkjastaur - Enclosure Post
Giljagaur - Crevice Imp
Stúfur - Itty Bitty
Þvörusleikir - Pot Scraper Licker
Pottasleikir - Pot Licker
Askasleikir - Bowl Licker
Hurðaskellir - Door Slammer
Skyrgámur - Skyr Gobbler
(Skyr, an Icelandic yoghurt)
Bjúgnakrækir - Sausage Snatcher
Gluggagægir - Window Peeper
Gáttaþefur - Doorway Sniffer
Ketkrókur - Meat Hooker
Kertasníkir - Candle Beggar

A few of the other names used for the Jólasveinar follow,
as they are descriptive of their natures, with an English translation:

Baggi - Bundle
Bandaleysir - Strap Loosener
Bjálfansbarnið - Idiot Child
Flotgleypir - Fat Gobbler
Hlöðustrangi - Barn Roll
Kleinusníkir - Donut Beggar
Lampaskuggi - Lamp Shadow
Móamangi - Moor Charlie
Reykjasvelgur - Smoke Gulper
Smjörhákur - Butter Greedy
Svartiljótur - Blackugly
Svellabrjótur - Icebreaker

As can be seen from the names the Jólasveinar are thought of
as playful imps, whose main interest seems to be to get their hands
on some of the seasonal food and other goodies.
Or they are lurking about trying to do some minor mischief.

When they first appeared the Jólasveinar had many of the attributes
of their parents, but soon started to seem milder,
and in the last century gained some of the attributes of their
Nordic counterparts, and in this century they have become
homegrown versions of St. Nick or Santa Clauses.

The Jólasveinar live in the mountains, and start to arrive in town,
one a day, thirteen days before Christmas Eve,
the last one arriving that morning.
They leave little presents for the children in shoes
that the children have put on the window sill the night before.
Or, if the children have been naughty,
they leave a potato, or some reminder that good behaviour is better.
Then they start departing for home again on Christmas Day,
and the last one departs on Þrettándinn.

At first the clothing of the Jólasveinar was just
the ordinary every-day wear of the common Icelander,
but in this century they have taken to wearing
the traditional red suits of St. Nick or Santa Claus.
In the last few years there has been a revival of the old style clothing.

This couple of child-eating, bloodthirsty ogres
are the supposed parents of the Jólasveinar.
The dominant member in the relationship is Grýla,
who according to some sources had another husband before Leppalúði.
His name was Boli. Boli, and later Leppalúði,
were bedridden and Grýla went around the countryside,
begging to support her husbands, and at Christmas time,
she stole children that had been naughty during the year.
Through the centuries Grýla has been a very popular means
of making children behave.
There are numerous lays and stories about Grýla and her exploits,
but she really never gets her hands on any children,
either they have been very well behaved through the year,
or they manage to escape.

For more information on the Jólasveinar: