The Kingdom of Norway as a unified realm dates to the reign of King Harald I Fairhair in the 9th century. His efforts in unifying the petty kingdoms of Norway resulted in the first known Norwegian central government. The country, however, soon fragmented and was collected into one entity in the first half of the 11th century, and Norway has retained a monarchy since that time. Traditionally, it has been viewed as being ruled by the Fairhair dynasty, though modern scholars question whether the eleventh century kings and their successors were truly descendants of Harald.

The Fairhair dynasty was a family of kings founded by Harald I of Norway which united and ruled Norway with few interruptions from the latter half of the 9th century. In the traditional view, this lasted until 1387, however, many modern scholars view this rule as lasting only three generations, ending with Harald Greycloak in the late 10th century. The moniker "Fairhair dynasty" is a retrospective construction: in their lifetime what little traces there are refer to them consistently as "Ynglings".