The
Ynglinga saga was originally written in
Old Norse by the Icelandic poet
Snorri Sturluson about
1225. He based it on an earlier
Ynglingatal which is attributed to the Norwegian
9th century skald Þjóðólfr of Hvinir, and which also appears in
Historia Norwegiae.
The Ynglinga saga is the first part of Snorri's history of the ancient Norse kings, the Heimskringla. It tells the most ancient part of the story of the House of Ynglings (the Scylfings of Beowulf). It was first translated into English and published in 1844.
The saga deals with the arrival of the Norse gods to Scandinavia and how Freyr founded the Swedish Yngling dynasty at Uppsala. Then the saga follows the line of Swedish kings until Ingjald ill-ruler after which the descendants settled in Norway and became the ancestors of the Norwegian king Harald Fairhair.
For a discussion on the controversy about the dating of the information, see Ynglingatal.