LONDON -- Canada-born opera singer Jon Vickers, nicknamed "God's tenor" for his inimitable voice and strong Christian beliefs, has died. He was 88.

The Royal Opera House opera, citing a statement from Vickers' family, said he died Friday in the Canadian province of Ontario after a struggle with Alzheimer's disease.

Born in Prince Albert, Saskatchewan, in 1926, Vickers sang as a child in church choirs and aspired to study medicine before winning a scholarship to the Royal Conservatory of Music in Toronto.

Vickers made his Royal Opera debut in 1957. A year later, he performed at Germany's Bayreuth festival, going on to become one of the world's leading performers of Richard Wagner, acclaimed for roles including Siegmund in "Die Walkuere."

From 1960, he was a regular at New York's Metropolitan Opera, where his signature roles included Benjamin Britten's "Peter Grimes."

Vickers stood out among dramatic tenors for the intensity of his performances and his richly powerful voice, described by critic John Ardoin as "holding a hundred colours and inflections."

"Art is a wrestling with the meaning of life," Vickers once said, and his religious faith informed his artistic choices.

Despite his association with Wagner's works, he found the German composer -- whose anti-Semitism made him a favourite of the Nazis -- morally objectionable. In 1977, Vickers pulled out of a production of Wagner's "Tannhauser," saying he considered it anti-Christian.

For three decades Vickers performed around the world, collecting devoted fans, numerous honorary degrees, companionship in the Order of Canada and two Grammy Awards.

Vickers retired in 1988. His family's statement said he was "a man of the land who was the most at home on his farm, surrounded by nature and his family."

His wife, Henrietta, died in 1991. He is survived by a sister, five children, 11 grandchildren and two great-grandchildren.