Heimskringla is a collection of sagas about Swedish and Norwegian kings, beginning with the saga of the legendary Swedish dynasty of the Ynglings, followed by accounts of historical Norwegian rulers from Harald Fairhair of the 9th century up to the death of the pretender Eystein Meyla in 1177. The exact sources of the Snorri's work are disputed, but they include earlier kings' sagas, such as Morkinskinna, Fagrskinna and the 12th-century Norwegian synoptic histories and oral traditions, notably many skaldic poems. He explicitly names the now lost work Hryggjarstykki as his source for the events of the mid-12th century. Although Snorri used these and other materials collected during his trips to Norway and Sweden, he composed the sagas himself.