Rarely is a thrall given any mentionable part to play in history. The reason Tormod Kark is mentioned is that his life was so tightly connected to Håkon ladejarl [Earl of Lade]. Håkon Sigurdsson is number five in the list of Norwegian kings, and was the most powerful man in Norway at the end of the Pre-Christian period.
Heimskringla [the book/saga listing all the kings of Norway written by Snorri Sturlason, the Icelandic poet and law sayer] tells us that Håkon and Kark were born on the same night. This may have been taken as a sign and contributed to giving them a special relationship. It is said that Kark was "given" to Håkon at an early point in time. Socially they were at the opposite ends of the social scale. But it is still easy to imagine that these two men of the same age had close contact when growing up together in Lade, thus sharing many experiences from an early age.
Håkon's father, Sigurd Jarl, was killed around 962. As Håkon came into more power, it is clear that Kark accompanied him as one of his most trusted men. Håkon lived a life full of conflict, probably spending much of his time in austerled [the East, particularly the Baltic and Russia]. After careful scheming he became the ruler of Norway around 970. He then controlled Norway north of Trondheim and western Norway southward to Agder. In the famous battle of Hjørungavåg on the coast of Møre (approximately 986) he fought Danish forces and Christian ideas. On this occasion Kark is written into history close by the side of his master.
But it is especially in the narratives relating to Håkon's demise that Kark steps out of the shadows and becomes a real character. It may perhaps be assumed that at this time he had reached a position where he could have purchased his freedom. But even so, he continued to stand shoulder to shoulder with Håkon. Håkon had at this time come into conflict with the societies around him, in part due to the way he conducted his personal life. At this time Olav Tryggvason was on his way north, bringing Christianity with him and with a strong desire to assume power over Norway. The details are of course quite vague, but in the final phase we know that Håkon and Kark escaped and were in hiding at the Rimol farm by Melhus, their backs against the wall. It is then alleged that Kark killed his master with a knife, only in the next instance to be killed by the new king's men. The heads of the Earl and Kark were both placed on stakes on Munkholmen to serve as a deterrent.
Many have later been interested in Kark's motives. Did the thrall kill his master hoping for freedom as a reward? Or may his intention have been more "modern", that he wanted to spare Håkon the fate awaiting him? It cannot be assumed that there were any witnesses to the deed, and it is also difficult to envision that Tormod Kark was given the opportunity to explain his actions. Thus this becomes pure speculation. The material nevertheless has inspired many – from Adam Oehlenschläger (1807) to contemporary authors such as the band Isenkram (Soga om Kark [The story of Kark], 1974), Peder W. Cappelen (1974) and Idar Lind (2000).