Historia Norwegie begins with the legendary Ynglingar and ends with the return of St. Olaf to Norway.
Historia de Antiquitate Regum Norwagiensium was written by a monk named Theodoricus, about whom little is known, and dedicated to Archbishop Eysteinn (d. 1188).
Despite its short length, the work includes fairly lengthy digressions, intended to have exemplary value.
Both the beginning and end of Ágrip are lost but the original scope of the work was probably from the legendary Halfdan the Black and down to 1177.
Ágrip may be regarded as a bridge between the learned Latin works and the later kings' sagas.