Richard Monette, the longest-serving artistic director of the Stratford Shakespeare Festival, has died at the age of 64.

Monette died Tuesday of a blood clot in his lung in a London, Ontario, hospital, the festival confirmed Wednesday.

Monette served as artistic director at Stratford, the largest repertory theater in North America, from 1994 to 2007. During his tenure, he improved the theater’s economic stability and shepherded it to record levels of attendance.

At a tribute to Monette held a year ago, Stratford alum Christopher Plummer, currently appearing there in a revival of Shaw’s “Caesar and Cleopatra,” called the artistic director “the man who wouldn’t quit.”

“The single most important thing he will be remembered for is that he saved this theater,” Mr. Plummer said.

“He was a brilliant actor, a gifted director, an inspiring artistic director, and a great Canadian,” said Des McAnuff, the theater’s current artistic director. “I will sorely miss his wit, his insight, his advice, and especially the warmth and wisdom that were among his many distinguished attributes.”

Monette was born in Montreal and attended Loyola College (now Concordia University) in Montreal before making his professional stage debut as Hamlet in Toronto.

He first landed at Stratford in 1965, when he appeared in “Henry IV,” parts 1 and 2, and in “Julius Caesar.”

From there, he went on to perform a multitude of stage roles in Toronto and London, England, and returned to Stratford in the early 1970s to take on a variety of classic Shakespearean roles. He also did television and appeared in the films “Iceman” (1984) and “I’ve Heard the Mermaids Singing” (1987).

In 1988, Monette turned to directing, scoring a success with his first major production, “The Taming of the Shrew.” He went on to helm more than 40 festival productions. Among the more memorable productions he directed were revivals of “Twelfth Night” (1994), “King Lear” (1996), “Camelot” (1997), and “The Tempest” (1999 and 2005).

A memorial service at the festival is planned.