Skjöldunga saga
The Skjöldunga saga (c. 1180 – 1200) was a Norse saga on the legendary Danish dynasty of the Skjöldungs, the same dynasty featured in the Old English poem Beowulf. The saga is lost in its original form but Arngrímur Jónsson paraphrased parts of it into Latin, and parts of it are thought to be preserved in other sagas, including Óláfs saga Tryggvasonar en mesta and Ragnarssona þáttr. It may relate to Saxo Grammaticus and contain a version of the story that ultimately inspired the lost Ur-Hamlet and ultimately William Shakespeare's Hamlet.
The fragments known as Sögubrot af nokkrum fornkonungum are believed to be based on the Skjöldunga saga, perhaps deriving from a late version of that work.
For an edition of materials relating to the Skjöldunga saga, see Danakonunga sögur, ed. Bjarni Guðnason, Íslenzk Fornrit 35 (Reykjavík, 1982). For an English translation by Clarence Miller of Arngrímur Jónsson's paraphrase, with introduction and notes, see the journal ANQ 20.3 (2007): 3-33.