Flateyjarbók (The Flatey Book) is an important collection of sagas of Norse kings, written at the behest of Jón Hákonarson, a wealthy farmer who lived in the Húnavatn district of northern Iceland. The book was scribed by two priests, Jón Þórðarson and Magnús Þórhallsson (who also illuminated the book), during the years 1387-1394.
The Flatey Book is the largest medieval Icelandic manuscript. It contains the oldest documented „ríma“ (lit: a rhyme), an epic poem about Olaf II Haraldsson, King of Norway from 1015 to 1028. Also of considerable importance are the only existing versions of Grænlendingasaga, which tells of the discovery of Vinland, and Eiríks saga rauða.
The Flatey Book was preserved for a long time in Denmark, but was among the first manuscripts that were repatriated to Iceland in 1971 as Icelandic treasures.
The Flatey Book plays a big role in the crime novel The Flatey Enigma, by Viktor Arnar Ingólfsson, which was published in English in 2011.