Templeton made his stage debut at
Worthing in 1828, appearing as Dermot in
The Poor Soldier. After some time in the provinces he made a successful London debut in October 1831 at the
Theatre Royal, Drury Lane. In 1832 he appeared as Raimbaut in the first British performance of
Meyerbeer's
Robert le diable. In 1833 he took the role of Don Ottavio in Mozart's
Don Giovanni at the
Royal Opera House, Covent Garden, at five days' notice. In 1833
Maria Malibran chose him as her tenor for
Bellini's
La sonnambula, at Covent Garden, and he continued as her leading tenor until her death in 1836. He visited Paris in 1842 before embarking on provincial tours, giving lecture recitals on Scottish, English, and Irish
folk-songs. In 1845–46 he went on a tour of the United States. Templeton had a repertoire of thirty-five operas, in many of which he created the chief parts. ==Retirement and death==