The Historia Norwegie names "Haraldus Comatus" as son and successor of "Halfdanus…Niger", recording that he reigned for 73 years and had 16 sons. Snorre names Harald as the son of Halfdan "the Black" & his second wife. According to Snorre, Harald was ten years old when he succeeded his father as King at Vestfold.

He conquered the area around Trondheim where Haakon Grjotgardson Jarl of Haalogaland accepted his overlordship. He was supported by the Jarl of Möre. The local rulers farther south joined forces against Harald, but were defeated in the naval battle at Hafrsfjord, after which Harald became ruler of all Norway as HARALD I "Hårfagre/Harfagri/Fairhair" King of Norway. He corresponded with Athelstan King of Wessex, and dispatched a mission to England led by Helgrim and Osfrid who presented Athelstan with an ornate warship at York. During his lifetime King Harald divided his kingdom between his sons and gave them all the title king. He decreed the title hereditary in the male line, and that his descendants in the female line should have the title Jarl. He granted:

Vingulmark, Raumarike, Vestfold and Thelamark to his sons Olav, Björn, Sigtryg, Frode and Thorgils;
Hedemark and Gudbrandsdal to his sons Dag, Hring and Ragnar;
Ringerike, Hadeland, Thoten and their dependencies to his sons by Snæfrid;
Hordaland and Sogn to his sons Hrorek and Gudrod;
Halogaland, North More and Raumsdal to his son Eirik;
his son Guthrom retained the lands which he already controlled;
the land north of Trondheim to Halfdan "the Black", Halfdan "the White" and Sigrod.

The division resulted in major disputes between his sons about who would inherit the overall kingship. The dating of this division is difficult to assess, but from the chronology of events recorded by Snorre it appears to have occurred before the birth of King Harald's son Haakon, which is dated to [919]. King Harald abdicated in 930 "when he was 80 years old" in favour of his son Erik, died three years later in 933, and was buried "under a mound at Haugar in Karmtsund, near the church in Haugesund".

http://fmg.ac/Projects/MedLands/NORWAY.htm#HaraldIdied934Or940B

Marriage Information:

Harald married Åsa HÅKONSDÓTTIR of Yrjar, daughter of Haakon GRJOTGARDSON and Unknown, before 874.

Marriage Information:

Harald also married Gyda "den storlåtne møya" EIRÍKSDÓTTIR of Hordaland. (Gyda "den storlåtne møya" EIRÍKSDÓTTIR of Hordaland was born about 852 in Hordaland, Norway.)

Marriage Information:

Harald also married Svanhild EYSTEINSDÓTTIR, daughter of Eystein "Glumra" IVARSSON Earl of More and Ascrida (Aseda) RÖGNVALDSDÓTTIR Countess in Uppsland, in Norway. (Svanhild EYSTEINSDÓTTIR was born about 850 in Maer, Nord Trondelag, Norway.)

Marriage Information:

Harald also married Snæfrid SVASESDÓTTIR.

Marriage Information:

Harald also married Alvhild RINGSDÓTTIR. (Alvhild RINGSDÓTTIR died on an unknown date.)

Marriage Information:

Harald also married Ragnhild "the Mighty" EIRÍKSDÓTTIR, daughter of Eirik, King in Jutland and Unknown, about 894. (Ragnhild "the Mighty" EIRÍKSDÓTTIR was born about 870 and died about 898.)

Marriage Information:

Harald also married Thora MOSTERSTANG Mistress. (Thora MOSTERSTANG Mistress died on an unknown date.)