It is the Old Icelandic translation of the Daretis Phrygii De Excidio Troiae Historia (Dares Phrygius’ History of the Destruction of Troy).
The saga expands on the basic framework provided by Dares to create a story with many particularly Norse elements and values.
Trójumanna saga Alpha, though the last to be discovered by modern scholars, is the closest to Dares' Historia in that it uses fewer supplementary sources than the other two versions.
After a brief war, Troy falls and Telamon takes Laomedon's daughter and Priam's sister, Hesione, back to Greece.
Priam, after rebuilding Troy, summons his five sons: Hector, Alexander (Paris), Deiphobus, Helenus, and Troilus, and they decide to avenge their grandfather, Laomedon.
He falls in love with Polyxena, Priam's daughter, is drawn into an ambush for her sake, and is assassinated by Alexander after a heroic last stand.