The opera director Julian Hope, who has died aged 59 of cancer, became in latter years the steward of his grandfather Somerset Maugham's literary estate. He had an encyclopedic memory for detail. As his friend the conductor Jane Glover put it, "there was no 'delete' in that brain". The hesitant, quietly-spoken authority which gave him an air of maturity as a young man never lost its underlying youthful enthusiasm in later life.
Julian was born in London but his family moved to Henley-on-Thames, Oxfordshire, where he grew up with his mother, Liza Maugham, only child of the novelist and granddaughter of the philanthropist Dr Barnardo. Julian's father was the Tory politician Lt Col Lord John Hope MP, later the 1st Baron Glendevon, and Julian inherited the title in 1996, but rarely used it. His parents' relationship with his famous grandfather was complex and the subject of bitter disputes, but Julian recalled visiting Cap Ferrat in the south of France as a child, on one occasion performing a creditable version of Knick-Knack Paddy-Wack for the ageing novelist.
At Eton college, Berkshire, in the 1960s he developed his artistic enthusiasms as lead guitarist and vocalist of the Hellfire Club and running the film study group, introducing the Antonin Artaud-scripted La Coquille et le Clergyman, a graphic account of clerical lust, and Luis Buñuel's Un Chien Andalou to his contemporaries. He also appeared in several stage productions, including Shaw's Caesar and Cleopatra, which visited Berlin, causing his father to exclaim: "You're at Eton, not Rada."
We met at Oxford in 1969 – he was at Christ Church – on the first day of term at the first audition it was possible to attend, and we were both cast (as first and third soldier respectively) in a play about the Norfolk rebellion, The Blood on the Marsh. However, it was success as a director rather than actor which propelled him towards his future career. His college entry won a drama competition and this led to an invitation by the university opera club to direct Stravinsky's Mavra. Among the cast were Glover and the young composer Stephen Oliver. The three became close friends and went on to work together on highly acclaimed student productions including a dazzling Figaro at the Oxford Playhouse and Oliver's brilliant first opera, The Duchess of Malfi, which Julian directed and Glover conducted.
After university, Julian went to Glyndebourne, where he assisted John Cox on his Hockney-designed Rake's Progress (1975), and Jean-Pierre Ponelle on his brilliantly understated production of Falstaff (1976). He went on to the Welsh National Opera, where he was a staff producer and directed Verdi's Il Trovatore and Puccini's Manon Lescaut. Over the next decade his work as an opera director was seen in productions across Europe and the US.
In 1980 Julian was invited by the impresario Michael White to stage a revival of The Rocky Horror Show, which later toured the US. He also directed several semi-staged productions at the Barbican in London, including Mendelssohn's A Midsummer Night's Dream, Molière's Le Bourgeois Gentil-homme, Stravinsky's A Soldier's Tale, with Gary Oldman, and a triumphal version of Rimsky-Korsakov's Milada.
His interest in film and his family history came together in his campaign to bring the wartime autobiographical Ashenden novels of his grandfather to the screen: the two-year quest resulted in a well-received BBC series in 1991. This success encouraged Julian to take a greater interest in his grandfather's literary estate, and he compiled lists of short stories and novels with synopses to take to producers and directors. As a result, several of Maugham's stories reached a new generation in films such as Up at the Villa (2000), Being Julia (2004) and The Painted Veil (2006).
He also acted as musical adviser on Michael Austin's comic satire Princess Caraboo (1994) and Martha Fiennes's elegant Onegin (1999). His final production was Jessica Douglas Home's Violet, a depiction in words and music of the pioneering harpsichordist Violet Gordon Woodhouse and her "scandalous" liaisons, which, suitably for a Rocky Horror director, was last seen in June at the Sibiu festival in Transylvania.
Julian is survived by his brother Jonathan, the art historian, who now succeeds as the 3rd Baron Glendevon.
• Julian John Somerset Hope, 2nd Baron Glendevon, opera director, born 16 March 1950; died 29 September 2009