The Oscar-winning playwright Sir Peter Shaffer, who wrote Amadeus, Equus and The Royal Hunt of the Sun, has died in Ireland aged 90.

Shaffer’s play Amadeus won worldwide acclaim when it hit the silver screen, while Equus was given a new lease of life in 2007, when Harry Potter star Daniel Radcliffe played the lead role in the West End.

“Peter Shaffer was one of the great writers of his generation,” said National Theatre director Rufus Norris. “The plays he leaves behind are an enduring legacy.” Radcliffe said he was “one of the UK’s greatest playwrights”.

Shaffer and his twin brother Anthony, the playwright who wrote Sleuth, grew up in a Jewish family in Liverpool but studied in London and then Cambridge.

He was gay, and his career tailed off after his partner Robert Leonard, a vocal coach, died in 1990. Still, Shaffer had written three successful plays, lauded by critics, if not always initially.

Writing in The Guardian, theatre critic Mark Lawson said: “The grand rhetoric and visual spectacle of The Royal Hunt of the Sun and Equus had been pejoratively called ‘operatic’ by some. Amadeus must be as close to a spoken opera as theatre has come. Shaping words into fugues and arias, the text resembles a libretto.”

He added: “Apart from the riches his production provided for the eyes, the other key to the Shaffer brand was that he wrote modern roles allowing great Shakespearean actors to use every note of their vocal instruments.”