rydel23, whose livejournal is notable for its interesting bilingual postings in English and Belarusian, has recently posted
Vienna - Wien - Wiedeń - Vídeň - Відэнь. The Belarusian language, it seems, has been much the most conservative, preserving the original Celtic "Vedunia" until the 20th century codification of the modern Belarusian language's grammar.