(b Leiden, 1733; d Vienna, 1803).
Dutch‐born Austrian patron of music. Went to Vienna 1745 when his father became empress's physician. Held diplomatic posts in Brussels, Paris, and London, and was ambassador to Berlin 1770–7. Prefect of Imperial Lib., Vienna, 1778–1803. Wrote light operas and syms., but remembered for commissioning works from C. P. E. Bach, Haydn, and Mozart. Introduced Mozart to mus. of Bach and Handel 1782–3. Mozart made his arrs. of Handel oratorios and other vocal works for private concerts van Swieten founded. Wrote or adapted texts of Haydn's Seven Last Words (ch. version 1796), The Creation (1798), and The Seasons (1801). Helped the young Beethoven, who dedicated his 1st Sym. to him.