The Poetic Edda (Elder Edda) by Anonymous, 13th C. CE

"The Poetic Edda is a later manuscript dating from the second half of the 13th century, but containing older materials (hence its alternative title, the Elder Edda). It is a collection of mythological and heroic poems of unknown authorship, composed over a long period (ad 800–1100). They are usually dramatic dialogues in a terse, simple, archaic style that is in decided contrast to the artful poetry of the skalds."

-summary taken from britannica 

Source:

https://www.sacred-texts.com/neu/poe/index.htm