Two collections of Old Norse writings are known by the title of Edda; together they form the most authoritative source for ancient Nordic mythology. The Elder, or Poetic, Edda is a collection of 34 Icelandic poems, interspersed with prose dating from the 9th to the 12th century. These anonymous poems use alliteration and a simple strophic form as their only formal devices. Most of them deal with Norse mythology and legend. The Younger, or Prose, Edda (c. 1220) is the work of the Icelandic poet and historian SNORRI STURLUSON. It was probably intended as a handbook for novice poets who wished to become skalds, creators of the sophisticated poetry recited in court. The Prose Edda contains a preface on the creation of the world; mythological stories; sayings attributed to the Norse god of poetry, Bragi; rules governing prosody; and an analysis of ancient poets.