The oldest attestations of toponyms on the Croatian territory originate from ancient sources, i. e. from the inscriptions and texts prior to the arrival of Slavic tribes on the East Adriatic coast. Some of these toponyms survived early medieval migrations and preserved their linguistic continuity in Croatian as early borrowings from Vulgar-Latin/early Romance. Due to various extralinguistic circumstances, linguistic continuity is better preserved in the coastal area than in the interior. By documenting and interpreting linguistic continuants of these toponyms throughout medieval sources, much can be said about the earliest contacts between Roman and Slavic people on the East Adriatic coast and also about the early Slavic (and Croatian) linguistic developments on the Croatian territory.
The aim of this paper is to analyze one category of these toponyms, specifically Croatian island names attested in medieval written sources from 9th–13th c (from the Croatian territory). This is the period in which the first written Slavic records on the Croatian territory appear. Nonetheless, the majority of these sources are documents written in Medieval Latin. The island names will be divided into those which have their equivalents in ancient sources and those which do not have such equivalents. A philological and etymological analysis of island names will be given. Where both exist, ancient and medieval attestations of island names will be contrasted. Special attention will be given to those attestations in which certain Slavic linguistic traits can be detected.