Original: He did not return to the Royal Opera House to conduct opera again until 1954, with Walton's Troilus and Cressida,The Times obituary notice, 4 October 1967, p. 12 although he did conduct the incidental music for a dramatisation of Pilgrim's Progress given at the Royal Opera House in 1948.
Simplified: He did not often conduct opera, but he did conduct at the Royal Opera House: in 1936 with Gustave Charpentier's opera Louise in 1936 and in 1954 the first performance of Walton's Troilus and Cressida.