Håkon IV (1204—December 15, 1263), also called Haakon the Old, was declared to be the son of Håkon III of Norway, the leader of the Birkebeiner, who had seized control over large parts of Norway in 1202. During an ongoing civil war between Birkebeiner and Bagler, who resisted in the regions Viken and Oblandene, Haakon III died shortly before the former was born in Folkisberg, Østfold in 1204.

When in 1206 the Bagler tried to take advantage of the situation and started hunting the heir, a group of Birkebeiner warriors fled with the child, heading for King Inge II of Norway in Nidaros (now Trondheim). On their way they came into a blizzard, and only the two mightiest warriors, Torstein Skevla and Skjervald Skrukka, continued on skis, carrying the child on the arm. They managed to bring the heir to safety. This event still is commemorated in Norway's most important annual skiing event, the Birkebeiner ski race.

So the child was placed under the protection of King Inge II, after whose death in 1217 he was chosen king. The church refused to recognize him until 1223 on the ground of illegitimacy and the Pope's dispensation for his coronation was not gained until much later.

In the earlier part of his reign much of the royal power was in the hands of Earl Skule , who intrigued against the king until 1239, when he proceeded to open hostility and was put to death. The rebellion also led to the death of Snorri Sturluson. From this time onward Haakon’s reign was marked by more peace and prosperity than Norway had known for many years, until in 1263 a dispute with the Scottish king concerning the Hebrides, a Norwegian possession, induced Haakon to undertake an expedition to the west of Scotland. A division of his army seems to have repulsed a large Scottish force at Largs (though the later Scottish accounts claim this battle as a victory), but won back the Norwegian possessions in Scotland.

Haakon was wintering in the Orkney Islands, when he was ill and died on December 15 1263. A great part of his fleet had been scattered and destroyed by storms. The most important event in his reign was his forcing the submission of the Icelandic Commonwealth. Worn out by internal strife fostered by Haakon’s emissaries, the Icelandic chiefs acknowledged the Norwegian king as overlord in 1262. Their example was followed by the colony of Greenland.

In 1240, a group of Bjarmians told Håkan that they were refugees from the Mongols. He gave them land in Malangen .