Thurneysen, Rudolf (1857–1940), Celticist, was born on 14 March 1857 in Basel, Switzerland, son of Eduard Thurneysen, silk manufacturer, and Eliza, daughter of Peter Merian, sometimes rector and professor of the natural sciences at the university of Basel. Among his teachers at the university of Basel were the great Jacob Burckhardt, the historian of the Italian renaissance, and Friedrich Nietzsche, the philosopher. From Basel he went on to Jena and Leipzig, where he obtained his doctorate in Latin philology, ‘Ueber Herkunft und Bildung der lateinischen Verba auf io’ (1879). He developed an interest in the Celtic languages under the tutelage of Windisch at Leipzig and Zimmer in Berlin, and finally under Gaidoz in Paris. He was appointed Privatdozent (lecturer) in Jena in 1882 and Professor extraordinarius in 1885. In 1887 he was appointed Professor ordinarius of comparative philology at Freiburg, when only 30 years of age, and he remained there until 1913, when he was appointed to the corresponding chair at Bonn, which he held until he became professor emeritus there in 1923. During 1911 he gave courses in the School of Irish Studies in Dublin. He left Bonn in 1925, and returned to Dublin in 1929 at the request of the Irish government to give a series of lectures on brehon law in the Royal Irish Academy (RIA). In 1927 he was elected a corresponding fellow of the Mediaeval Academy of America. He was a master of many languages, including Greek, Latin, Italic and Gothic, Germanic, and the Celtic languages, not to mention the modern Romance languages. He began to study modern Irish at the end of the nineteenth century under the inspiration of Douglas Hyde (qv) and the Gaelic League.
His first contribution to Old Irish studies was in collaboration with Bruno Güterbock, an index to Zeuss's Grammatica Celtica, ‘Indices glossarum et vocabularum hibernicorum quae in Grammatica Celtica explanantur’. His next contributions to Old Irish studies, published in Revue Celtique, vi (1883), were on the principles of the Old Irish verbal accent, in the discovery of which he preceded Zimmer. After the establishment of the Zeitschrift für celtische Philologie in 1897, his contributions helped to make it the foremost journal in its field of its time. His major opus was the Handbuch des Altirischen, published in 1909, and published in an English edition by Osborn Bergin (qv) and Daniel Binchy (qv) in 1946, with many additions by the author to the first edition. It remains the standard authority on the subject. In 1921 he published his fundamental study of the Irish hero- and king-sagas, Die irische Helden- und Konigsage bis zum siebzehnten Jahrhundert, based on the recensional and literary analysis of many texts still in manuscript, and his separate edition of Scéla mucce Meic Dathó (‘The story of Mac Dathó's pig’) is a model of the type. The last fifteen years of his life he devoted to the study of early Irish law, culminating in the publication of his Studies in early Irish law. The results of his labours are an extraordinary achievement in a very difficult field for a scholar with no legal training. He continued throughout his career to make contributions to Indo-European linguistics in Kuhns Zeitschrift, Indogermanische Forschungen, and Abhandlungen der preussischen Akademie.
Thurneysen's significance for the study of early Irish language, literature, and law cannot be over-estimated. His publications are of seminal importance, executed with a critical acumen and balance of judgement such as few scholars have achieved. He taught two generations of Celticists from both sides of the Atlantic in the universities of Freiburg and Bonn, including D. A. Binchy, Tomás Ó Máille (qv), Osborn Bergin, Robert A. S. Macalister (qv), Kathleen Mulchrone (qv), Francis Shaw, Fred Robinson, and many others. He was given an honorary doctorate from the National University of Ireland (NUI) in 1925, and in 1927 both Indogermanische Forschungen (vol. xlv) and Zeitschrift für celtische Philologie (xvii) were published in honour of his seventieth birthday.
He married (1893) a native of Munich and had two daughters. He died on 7 August 1940, and was survived by his wife (of whom nothing is known) and his family. As a true Swiss, he pursued his love of mountain-climbing up to his eighty-second year.
More information on this entry is available at the National Database of Irish-language biographies (Ainm.ie).