Venerated soprano Maria Callas played her role in many a tragedy, but her life off stage was no less dramatic or colourful with accusations that she was drugged by her lover Aristotle Onassis for sex, unpublished letters have revealed.
Biographer Lyndsy Spence has spent the last two years sifting through three collections of previously unseen material, which document the extent to which Callas felt she was abused and ill-treated by those close to her, The Observer reports.
The startling revelations, which also include the singer being blackmailed by her mother and swindled by her husband, appear in Spence's new book, Cast A Diva: The Hidden Life of Maria Callas, which is published by The History Press on 1 June.
Maria Callas was blackmailed by her mother, swindled by her husband and drugged by her lover, unpublished letters have revealed in a new book by historian Lyndsy Spence
In never-before-seen letters, Callas alleges that lover Aristotle Onassis - who was married to Jackie Kennedy - physically threatened and drugged her
In another letter, Callas referred to her husband Giovanni Battista Meneghini as a 'louse'
Among the most shocking are letters to her secretary in which Callas reveals shipping magnate Aristotle Onassis - who was married to Jackie Kennedy and with whom Callas had a long-running affair - physically threated the singer.
Spence says of the letters from 1966: 'There is also disturbing information from the diary of one of her close friends detailing how Onassis drugged her, mostly for sexual reasons - today we would class that as date rape.'
Who was Maria Callas?
Born Maria Anna Cecilia Sofia Kalogeropoulos on December 2, 1923 in New York City
She left the United States in 1937 to study at the Athens Conservatory
Callas established her career in Italy
In 1949 she married industrialist Giovanni Battista Meneghini
In 1957 she met Aristotle Onassis and carried on a long affair with him, despite the fact they were both married
In 1966 she became a Greek citizen and relinquished her US citizenship
By the time Callas retired she had performed more than 40 roles and recorded more than 20 operas
In 1971 she divorced Meneghini
Callas spent her last years living largely in isolation in Paris
She died of a heart attack aged 53 on September 16, 1977
Love equally evaded her in her marriage to Italian industrialist Giovanni Battista Meneghini, who Callas referred to as 'a louse'.
She wrote: 'My husband is still pestering me after having robbed me of more than half my money by putting everything in his name since we were married...I was a fool...to trust him.'
In other letters, Callas alleges that she was stopped from returning to Juilliard School in New York to teach after she rebuffed advances from then president Peter Mennin.
She was equally scathing of her mother, who Callas said sold stories to the press and blackmailed her.
But it was for her long-time soprano rival Renata Tebaldi that Callas reserved the most vitriol.
During the 1950s the two singers were involved in a public spat, after Tebaldi said: 'I have one thing that Callas doesn't have: a heart.'
Meanwhile, Callas spoke about their respective voices, saying that to do so was like 'comparing champagne to cognac'.
Each dismissed their supposed rivalry as made up by the media, but now a previously unpublished letter challenges that supposed truth.
'She's as nasty and as sly as they come,' wrote Callas.
In her later years, Callas' longstanding affair with Onassis ended and she divorced her husband in 1971.
She spent her last years living largely in isolation in Paris and died of a heart attack in 1977, aged 53.
She was adored on stage, but love evaded Maria Callas in real life, a new book claims
The book also sheds new light on Callas' rivalry with fellow soprano Renata Tribaldi