Sir John Tavener

Sir John Tavener, who has died aged 69, was the most spiritual of modern English composers, a man of immense presence (he was six-and-a-half feet tall, with long, lank hair and a monkish demeanour) and chronic ill-health (he suffered from an obscure syndrome that caused his aorta to leak, had a stroke that partly paralysed him in 1980, and in recent years had heart surgery along with a long period in intensive care). He possessed deep religious faith and an obsession with musical giganticism that produced his seven-hour vigil, The Veil of the Temple, successfully premiered in London's Temple Church in 2003.

Not to be confused (though inevitably he was) with the fifteenth-century English composer and heretic John Taverner, from whom he once claimed to be descended and upon whom Sir Peter Maxwell Davies based a sensational opera, he was born into a Presbyterian London family and displayed from an early age the religious leanings that eventually developed into the spiritual universalism he shared with his friend Prince Charles.

It was to the Prince of Wales, indeed, that he dedicated his oratorio Fall and Resurrection, another major work, in which he employed exotic instruments (folk flutes and rams' horns) to demonstrate his increasing devotion to eastern religions. Charles attended its first performance at St Paul's Cathedral in the year 2000, three years after the mesmerising Song for Athene had been sung - to a world-wide audience - at the end of Princess Diana's funeral service in Westminster Abbey.

Yet Sir John was not a royalist composer in the old Elgarian sense. His theological values were what sustained him, and which resulted in The Protecting Veil, his huge romantic "icon in sound" for the cellist Steven Isserlis, inspired by the Mother of God and first heard, with equally huge success, at the London Proms in 1989. Though audience response seemed to matter much to him, he welcomed it for what he perceived to be its spirituality as much as, if not more than, anything else.

Devotion, indeed, was what inspired him from his earliest days, in such works as his cantata The Whale, telling the story of Jonah in scintillatingly modern musical terms and recorded with the financial support of his great admirers the Beatles under their own Apple label, along with its successor A Celtic Requiem, which achieved acclaim simultaneously with the rise of Andrew Lloyd Webber, though Sir John never cultivated that sort of populist idiom.

His larger works could be quite an endurance test. His celebrated Akhmatova Requiem, premiered at the 1981 Edinburgh Festival, was one such, not least because printed programmes - a vital aid to proper understanding of what it was about - were hard to find before the start of the hour-long performance conducted by Gennadi Rozhdestvensky at the Usher Hall.

Though it was said to have formed the least popular event in Sir John Drummond's entire period as festival director, it soon afterwards did little better at the London Proms. Not until it reached Moscow some years later did it emerge triumphant, but by then the tide had turned irreversibly in Sir John's favour.

The atmospheric premiere of his three-hour Resurrection, given by Cappella Nova (with, confusingly, a different Tavener, the unrelated Alan Tavener, as conductor) and the Scottish Chamber Orchestra, certainly attracted a vast crowd to Glasgow Cathedral in 1990, when Michael Tumelty, in his review for The Herald, hailed it for its heavenly length. With Christ surrounded by a halo of trumpets, the performance, in the composer's "flushed" presence, was described as a major event.

Yet the music was once again hard work - in a way that Bach's St Matthew Passion is not - for anyone who could not share the composer's spiritual fervour or the way in which he expressed it. The old Stravinskyisms which had cut their way into The Whale and other early works - he was a deep admirer of the Canticum Sacrum written for St Mark's, Venice, in 1956 and deemed it the pinnacle of twentieth-century music - had long since gone. The slow serenity of his mature style seemed to some ears to have more in common with the fashionable luminosity of Arvo Part and of the tonal inertia of Gorecki's Symphony of Sorrowful Songs.

It was, however, a sound which brought this enormously prolific composer a new mass appeal. Though the death of his beloved mother in 1985 briefly stemmed the flow, his first meeting with Mother Thekla, abbess of the Greek Orthodox Monastery of the Assumption on the North Yorkshire moors, set him going again. Many of his subsequent works were derived from Orthodox spirituality and employed Orthodox modes. It was she who suggested to him the idea of The Protecting Veil, which, when it was recorded in 1992, became Britain's best-selling classical disc.

Born in Wembley, Sir John was the son of a surveyor who successfully restored stately homes. Taken as a child to see The Magic Flute at Glyndebourne, he was spellbound by its religious symbolism as well as its comedy. At 13, he won a scholarship to Highgate School, singing in the school choir, which rose to a BBC performance of Mahler's Third Symphony, and befriending Nicholas Snowman, the future founder of the London Sinfonietta, which made its debut with the premiere of The Whale.

As a pianist he played Beethoven's Fourth Piano Concerto with the school orchestra and when, in 1962, he progressed to the Royal Academy of Music his hopes were to become a concert pianist. But nerves turned him instead towards composition, with Lennox Berkeley as his teacher. By the time he was 20, his Three Holy Sonnets were conducted by Paul Steinitz at St Bartholomew-the-Great.

Unstopped by pain, he went on composing to the end. His violin concerto, entitled Lalishri, for the Scottish violinist Nicola Benedetti was composed in 2007. His Requiem for cello, vocal soloists, chorus, and orchestra, employing Sufi poetry, the Catholic Mass, the Koran and Hindu words, had its premiere in Liverpool Metropolitan Cathedral in 2008, though the composer was too ill to attend the performance.

In June this year three new works were heard at the Manchester International Festival, one of them a monodrama based on Tolstoy's Death of Ivan Ilyich, where the central character seeks redemption as he stares into the void of death.

He was knighted in the New Year Honours List in 2000, in the wake of the Hogmanay performance of one of his works at the Millennium Dome in Greenwich. He was married twice, in 1974 to the Greek dancer Victoria Maragopoulou, from whom he separated after eight months, and then in 1991 to Maryanna Schaefer, with whom he lived in Sussex and latterly in Dorset, and by whom he had three children, Theodora, Sofia, and Orlando. She and they survive him.