The Children of Adam and Eve

He was the first to rule, at least nominally, the entire country. Harold
inherited three small domains in eastern, central, and western Norway from
his father, and set out to conquer the rest of the country, spurred --
according to the saga tradition -- by the refusal of another petty king's
daughter to marry him until all of Norway was under his sway. After many
years of campaigning, during which the chieftains of western Norway
offered the most stubborn resistance, Harold gained his final victory in
the Battle of Hafrsfjord, which probably took place around 885, although
it may have been some years later.

Once in power, Harold ruled with a Strong hand and consolidated his realm.
One result of his firm rule was the acceleration of the immigration that
had begun shortly before to pioneer settlements in Iceland. Many
chieftains also fled to the Western (British) Isles, from where they and
their kinsfolk in the Orkneys, Shetlands, and Hebrides raided the
Norwegian coast. Harold was finally compelled to send a punitive
expedition aCross the North Sea to flush out these Vikings. For the same
purpose he entered into an alliance with King ?helstan of England; but he
made no actual conquests. In his old age Harold abdicated in favor of his
eldest legitimate son, Eric Bloodaxe, who was deposed by his half Brother
Haakon I after a few years of misrule.