"Gísla saga" survives in thirty-three manuscripts and fragments from the Middle Ages down to the twentieth century. It is generally thought to have been composed in written form in the first half of the thirteenth century, but the earliest manuscript, the fragment Reykjavík, Stofnun Árna Magnússonar, AM 445 c I 4to, is from around 1400 and the earliest extensive text in AM 556a 4to, from the later fifteenth. The saga is generally thought to exist in three main versions originating in the Middle Ages: