Peter Donaldson, an acclaimed and prolific Canadian actor of the stage and screen, has died after a two-year battle with lung cancer. He was 57.

Peter Donaldson spent 25 years at the Stratford Shakespeare Festival, debuting in 1977 in Romeo and Juliet. (Stratford Festival)

Donaldson died Saturday in a Toronto hospital. Few details have emerged concerning his illness and death.

The versatile actor, known for his Shakespearean roles, captured a supporting-actor Genie in 1996 for his work in the film version of Long Day's Journey Into Night. He also appeared in Atom Egoyan's The Sweet Hereafter and portrayed Ian Bowles on the series Emily of New Moon.

But for a large part of his career, Donaldson stormed the stage at the Stratford Festival in Southern Ontario.

"Peter was the finest actor's actor. He was deeply admired for the conviction he brought to his work and the unsparing truth of his portrayals," Antoni Cimolino, the Stratford Festival's general director, said in a statement issued Sunday.

"He was versatile and able to give outstanding performances in modern plays, musicals and classics. But his home was Shakespeare."

Theatre critic Martin Morrow, who writes about the arts for CBCNews.ca and is the author of Wild Theatre, said seeing Donaldson's name in a program meant one was "guaranteed a witty, rich and deep performance."

" Peter Donaldson was one of Canada's acting treasures, a consummate classical actor with a gorgeous voice just made for speaking Shakespeare. He was so at ease on Stratford's Festival stage, you felt like he was in his living room," said Morrow.

"He was wonderful just a few seasons ago as Rufio, right-hand man to Christopher Plummer's Julius Caesar in Caesar and Cleopatra at Stratford. The byplay between those two veteran actors was a delight to behold. And he was equally at home in contemporary work. I loved him last season as Ned, the downwardly mobile suburbanite in George F. Walker's And So It Goes [at Toronto's Factory Theatre]."

Married to Sheila McCarthy for 25 years

Donaldson's wife is fellow actor Sheila McCarthy, who appears as Sarah Hamoudi on the CBC's Little Mosque on the Prairie and also had a starring role on Emily of New Moon. They had been married for 25 years.

Christopher Plummer (left) as Caesar and Peter Donaldson as Rufio, in a still from the film version of Stratford Festival's Caesar and Cleopatra, staged in 2008. (David Hou/Stratford Festival)

The couple, who split their time between Toronto and Stratford, Ont., have two daughters.

Actress Andrea Martin posted a tweet Sunday "impossible to believe that my friend Peter Donaldson has passed away. So deeply sad for his daughters & wife Sheila who he was devoted to."

Donaldson's various stage roles, many at the Stratford Festival, have included major parts in Glengarry Glen Ross, To Kill a Mockingbird, King Lear, Much Ado About Nothing, Hello Dolly!, Guys and Dolls, Antony and Cleopatra, Who’s Afraid of Virginia Woolf?, Twelfth Night, The Taming of the Shrew, Hamlet and King Lear.

After graduating from the University of Guelph, Donaldson embarked on his stage career with a Stratford debut in Romeo and Juliet in 1977. He continued to make his mark during his quarter-century at the annual festival.

In recent years he was also lauded for parts he played in productions at Soulpepper Theatre including their original 1999 production of Our Town and 2009's Glengarry Glen Ross.

Cimolino says Donaldson was still improving on his craft.

"Peter was now coming into the best, deepest and richest part of his talent," noted Cimolino. "We will not know exactly what we have lost from his sad early passing. We are only left to wonder and mourn."