Who dated Inga of Varteig?

Inga Olafsdatter of Varteig (Inga Olafsdatter fra Varteig) (Varteig, Østfold, 1183 or c. 1185 – 1234 or 1235) was the mistress of King Haakon III of Norway and the mother of King Haakon IV of Norway.

Haakon III Sverresson (Norwegian: Håkon Sverresson, Old Norse: Hákon Sverrisson; c. 1183 – 1 January 1204) was King of Norway from 1202 to 1204.