The present monograph deals with the A-redaction of the Old Swedish text Tungulus/Tundalus. This work is a translation and/or adaption of the Latin text Visio Tnugdali, present in a large number of manuscripts in medieval Europe. The Old Swedish A-redaction exists in four manuscripts that are of relevance for its early transmission: Cod. Holm. D 4a (c. 1448, 1449–1463), Cod. Holm. D 3 (c. 1487/1488), Cod. Linc. Saml. 1a (late 15th century or early 16th century) and Cod. Holm. K 45 (1525–1550). The investigation aims at mapping the rela-tionship between these textual witnesses through a comparison of the variation between them, with regard to the following categories: 1) absence/presence of textual elements, 2) lexical variation, 3) syntactic variation with respect to word order and 4) morphological variation with respect to different inflectional forms of the same lemma. This investigation resulted in the following relationship (Greek letters representing now lost steps): α – D 4a – β – D 3 –( γ –) Linc. 1a – K 45 Following this, an investigation is carried out into the case morphology of the textual witnesses, focusing on how the scribes have dealt with this aspect in the copying process. All the textual witnesses have originated during or after the assumed time of the loss of the four-case system. All textual witnesses contain variation between forms inflected according to the older system and forms not conforming to this. However, although there is considerable general variation between inflected and non-inflected forms, it turns out that the inflected and the non-inflected forms are found in the same positions in the different textual witnesses. It appears that all the scribes of the investigated textual witnesses have largely followed their exemplars on a morphological level, rendering the case forms found there, and thus disregarding their own linguistic norm. Keywords: Tungulus/Tundalus, textual criticism, Old Swedish, medieval scribes, case morphology Språk i boken: Svenska