This article examines the history of the Old Icelandic front mid vowel /ø/, and considers its fate in the history of Icelandic. In most cases this vowel merges with the originally back and rounded /ǫ/. Thus the modern Icelandic reflex of OI søkkva has the same vowel as that of hǫggva, both with the MI phoneme ö [œ], usually classified as a front rounded low mid vowel. In a number of cases, however, the old /ø/ was delabialised and has the MI reflex /e/ ([ɛ]), as in kemur (< OI kømr).

After reviewing former attempts at accounting for the development of the old /ø/ (e.g. Noreen 1970 (1923), Leijström 1934, Sveinn Bergsveinsson 1955, Hreinn Benediktsson 1959, Stefán Karlsson 1981) the article moves on to suggest that the fate of the ø-vowel was determined by a complex of events and trends in the history of Icelandic. Phonologically, or phonetically, there was a trend or “metarule” (cf. Lass 1974, 1976) toward delabialising /ø/ as well as other front rounded vowels (ý > í, y > i, ǿ > æ). At the same time, there probably was a tendency toward centralisation of the old short vowels, among them the old /ø/ and /ǫ/, fronting the latter, and perhaps backing the former. This trend interfered with the delabialisation trend, and had the effect that in a great number of forms the old /ø/ leaned toward the old /o/ to form the new /ö/-phoneme. In many cases it seems that a following front unrounded vowel enhanced the delabialisation, e.g. in words like erindi and erlendur < ørendi, ørlendr. The morphology also had an effect in regularising some alternations between rounded and unrounded vowels in forms like koma – kemur, and later, or dialectally, sökkva – sekkur. To add to the confusion and uncertainty about the fate of the old /ø/, it is likely that different dialects had a different influence at different times on the development of the standard and the written language. All of this had the effect that the correspondence between the standardised OI and the modem norm is not a simple one in the case of the old ø. A phoneme is dissolved, and its ‘homeless’ tokens are distributed among the neighbours under more than one influence.