The Poetic Edda is the modern name for an untitled collection of Old Norse anonymous poems, which is distinct from the Prose Edda written by Snorri Sturluson. Several versions exist, all primarily of text from the Icelandic medieval manuscript known as the Codex Regius, which contains 31 poems. The Codex Regius is arguably the most important extant source on Norse mythology and Germanic heroic legends. The Prose Edda, also known as the Younger Edda, Snorri's Edda (Icelandic: Snorra Edda) or, historically, simply as Edda, is an Old Norse textbook written in Iceland during the early 13th century. The work is often assumed to have been to some extent written, or at least compiled, by the Icelandic scholar, lawspeaker, and historian Snorri Sturluson c. 1220.