You might have heard some versions of the story of Freyfaxi. It's funny how different writers take old themes and change them either a bit or drastically. Just like the Disney company took the tragic true and horrid story of Anastasia and changed it so that it somehow became a romantic adventure for kids!!!
Anyway, the original, and true story of Freyfaxi is very old, and it happened in Iceland between the years 900-950. I'll tell it here in a shortened version. The icelandic sagas were written and have been preserved over the centuries, and have not changed very much. They have thus much truth in it, sometimes the story tellers changed some nuances to make the story better to listen to, but they are in many ways also historical references, and are treated with much respect by both Icelanders and historians.
It is about the icelandic clan-chief Hrafnkell Freysgodi. The icelandics at that time were what some of you might recognize as vikings.
Hrafnkell's religion was of the old scandinavion gods. He had a blue dun stallion, that lived and roamed in the mountains beside Hrafnkell's farm, with a herd of mares. Hrafnkell had a lot of faith in the god of agriculture, gifts and fertility; Freyr. So, he gave Freyr half his stallion, and he made an oath that if any other man than Hrafnkell himself rode this horse, he's kill him. Oaths were not to be taken lightly at this time, if a man made an oath he had to fulfill it. The horse was called Freyfaxi, Freyr after his godly owner, and Faxi is a common name for horses (meaning eye-catching mane).
Hrafnkell hired the oldest son of his neighbour, which name was Einar. Einar was, for 2 years, to take care of 50 sheep that Hrafnkell owned, drive them to pasture every day and back home again to near a mountain-cabin in the evening, and also to cut the firewood that was needed for the farm. He was also supposed to look after Freyfaxi and his 12 mares in the mountains. Hrafnkell told Einar about his oath, and forbade him to ride Freyfaxi, but Einar could use any of the other horses for whatever he needed, whenever he needed, which Einar thought was very fair.
Einar did a good job at taking care of the sheep all summer, untill about midsummer, when he couldn't find 30 of the sheep. He searched and searched, but for a whole week he couldn't find them. Sheep were very valuable in those days, and this was a terrible mishap. Once, in his search, he walks past the horses, and wants to catch one of them for the search. The horses, that were used to being easy to catch, all ran away from him, exept Freyfaxi, that stood still like a rock. Einar sees that the day is passing, and he decides that Hrafnkell won't know even though he rides the horse, puts a bridle in his mouth, a pad on his back, and rides and search for the sheep from morning to late evening. The horse was willing and hard working, and he can search a great area, and in the end Einar finds the sheep and drives them home along with the other sheep.
The horse was all wet from sweat, so it was leaking from every hair, he was very muddy and panting. He rolled 12 times, neighs loudly, and runs down the road. Einar runs after him, tries to get in front of him to bring him back to his mares, but Freyfaxi didn't let himself be caught and Einar couldn't get near him.
The horse runs down the valley and doesn't stop untill he's home at Hrafnkell's farm, Adalbol. Hrafnkell was eating, and when the horse came to the door, he neigh's loudly. Hrafnkell said to a woman, that was serving, that she should go to the door, as a horse was neighing, and "it sounds like Freyfaxi". She does that, and sais Hrafnkell that Freyfaxi is by the door, looking dirty.
"Why is that?" sais Hrafnkell, "this does not come from good reasons".
So he walks out, sees Freyfaxi, and sais "I'm sad that you have been treated this way, but you were wise when you told me, and this will be revenged. Go to your horses". And Freyfaxi walks straight away up the valley to the mares.
The next morning Hrafnkell rides up to the mountain cabin, with an axe with him. Einar had just driven the sheep to the cabin, and they were being milked by wimen. They talk for a while, untill Hrafnkell asks him whether he had taken Freyfaxi, which wasn't allowed. Einar said he couldn't deny that.
Hrafnkell said "why did you ride this horse, since I had forbidden that, and there were so many that you were allowed to ride? I would have forgiven you that if I wasn't bound by this dire oath, but you've behaved well when you admitted this". And Hrafnkell ran to him and gave Einar a fatal blow. Later he had a respectable gravesite made for the young man.
Einar's father was of course not happy about this, and this is just the beginning of a long and tragic saga. Hrafnkell is in many ways bound by fate in this story, it's fate that makes the mare so jumpy so Einar couldn't catch them, and the deep meaning of oaths in those days makes it impossible for Hrafnkell to break the promise he had made to his god, however sad it made him. It was also going to sour his whole life, he made many enemies and had to fight his whole life as a consequence of this deed.
http://www.icelandichorse.is/freyfaxi.htm