Poetic Edda is the modern attribution for an unnamed collection of Old Norse anonymous poems, which is different from the Edda, written by Snorri Sturluson. Several versions exist, all consisting primarily of text from the Icelandic medieval manuscript known as the Codex Regius. The Codex Regius is arguably the most important extant source on Norse mythology and Germanic heroic legends, and from the early 19th century onwards, it has had a powerful influence on later Scandinavian literatures, not merely by the stories it contains but also by the visionary force and dramatic quality of many of the poems. It has also become an inspiring model for many later innovations in poetic meter, particularly in Nordic languages, offering many varied examples of terse, stress-based metrical schemes working without any final rhyme by instead using alliterative devices and strongly-concentrated imagery. Poets who have acknowledged their debt to the Codex Regius include Vilhelm Ekelund, August Strindberg, J.R.R. Tolkien, Ezra Pound, Jorge Luis Borges, and Karin Boye.
Codex Regius was written in the 13th century, but nothing is known of its whereabouts until 1643, when it came into the possession of Brynjólfur Sveinsson, then Bishop of Skálholt. At the time, versions of the Edda were known in Iceland, but scholars speculated that there once was another Edda, an Elder Edda, which contained the pagan poems that Snorri quotes in his Edda. When Codex Regius was discovered, it seemed that the speculation had proved, but modern scholarly research has shown that Edda was likely written first and the two were, at most, connected by a common source.