Slysa-Hróa saga, or The Tale of Roi the Fool, is a short Icelandic saga preserved in four different versions, two of them medieval. One of them (F) is a þáttr woven into Óláfs saga helga (the Saga of St. Olaf) in the manuscript Flateyjarbók, written ca. 1387, while the other (A) is found in the 15th-century manuscript AM 557 4to. Two other versions,B and C, are preserved in manuscripts from the 17th century and later. They presumably derive from the A version, probably through a lost intermediary manuscript, β. The A and F versions seem to go back to a lost common original, α. The four versions are preserved in a total of 30 manuscripts: F in Flateyjarbók and 11 copies of that text; A in one manuscript; B in 8 manuscripts; C in 6 manuscripts; and there are also three other manuscripts transmitting an abbreviated or contaminated B/C text. The saga tells of a man who undertakes a trade mission to a foreign country. In F he travels to Sweden, but in B/C he goes to England. There he meets ruthless villains who attempt to take his life and steal his belongings. He is helped by a wise man (Þorgnýr Lawspeaker or Þorgnýr the Wise) and finally he stands as a winner. The story is given a historical framework. In F (and A?), it is the reign of St. Olaf Haraldsson (king ofNorway 1015–1028), the almost contemporary Svend Forkbeard (king of Denmark ca. 986–1014) and the slightly older Eric the Victorious (king of Sweden ca. 970–995). In B and C (and A?) it is again the time of St. Olaf but also the considerably younger Svend Estridsen (king of Denmark 1047–1074/76). Despite its Nordic character, the story is without doubt built on a tale with Oriental roots and from the same stock of adventures that underlies the Arabian Nights. The story also shows similarities with the Middle French romance L’Histoire du Chevalier Bérinus, from the 14th century and the Middle English Tale of Beryn, from the 15th century. The most prominent characteristic of Slysa-Hróa saga in its present redactions is its division into four text units. Most of the story in all its redactions (text units 2 and 4) has a common origin, while a smaller portion of the text (units 1 and 3) stems from different sources in F/A and B/C respectively. There is much to suggest that B/C is based on a lost copy of A (β) made after one folio had been lost from the beginning of A and another from its middle. Either a presently unknown manuscript (γ) was then used to fill up these two gaps, or else the person who transcribed A composed a new text, either from memory or through dictation. Slysa-Hróa saga is edited here from F, A and B¹ (AM 587 a 4to), with variant readings from four B manuscripts and a selection of readings from C manuscripts. The A and B versions have not been previously published.