Thea King is considered the doyenne of British clarinetists, particularly known for promoting twentieth-century British clarinet music. A greatly loved and respected figure in British music, she had one of the leading international concert and recital careers in the history of the instrument. She actually began as a piano scholarship student at the Royal College of Music, but she was the star pupil of the best-known English clarinetist of his time, Frederick "Jack" Thurston, whom she married in 1953. That was, sadly, also the year of his death at the age of 52. His 24-year old widow carried on in his tradition, becoming the most highly regarded clarinet teacher of her generation and a tireless champion of British music. Thurston had given the premiere performances of chamber music works with clarinet by a number of English composers, many of which were written with his warm tone in mind, as well as the British premieres of the clarinet concertos of Carl Nielsen, Aaron Copland, Paul Hindemith, and Darius Milhaud. Likewise, King premiered such works as Benjamin Frankel's Clarinet Quintet, Humphrey Searle's Suite (1956), Arnold Cooke's Clarinet Sonata, and John Ireland's Sextet, and presented the first recording of the long-forgotten single movement that Benjamin Britten wrote of a planned clarinet concerto. She also frequently performed, and recorded, the Charles Villiers Stanford's Clarinet Concerto, a work with which her husband was closely associated. King became principal clarinet of the London Mozart Players in 1956 (until 1984), and in 1964 took a similar position with the English Chamber Orchestra. She was a member of the Portia Ensemble (1954 - 1968) and the Melos Ensemble (from 1974). In 1961, she began teaching clarinet at the Royal College of Music in London, and became a professor at the Guildhall School of Music and Drama in 1988. She pursued her long career as soloist, chamber player, orchestral player, and teacher in many locations around the world, giving master classes and making appearances at major concert venues in Europe, Britain, Hong Kong, Japan, Brazil, and North America. She was well known for her performance of the major Mozart works featuring the clarinet: the Clarinet Concerto, the Clarinet Quintet, and the Kegelstatt Trio. She was adept on the related instruments, the basset horn and the basset clarinet, and played the Mozart concerto and quintet on its originally intended instrument, the basset clarinet. She also played piano, and by overdubbing recorded all three instrumental parts in Mendelssohn's Concert Piece, Op. 114, for clarinet, basset horn, and piano for a BBC Radio series, Double Exposure. In addition to the standard clarinet repertory and British works, King had a strong interest in the largely forgotten clarinet works of the nineteenth century. She recorded all three clarinet concertos and the clarinet quartets of Crusell, as well as works by Tausch, Heinze, Süssmayer, and Andreas Romberg, and the major repertory works with clarinet by Johannes Brahms. Thea King was awarded the Order of the British Empire in 1985 and in 2001 was created a Dame of the British Empire. She recorded on the Hyperion label.