Mr. Barnes was 73. His 1968 play The Ruling Class was a critique of the powers that be in England: The wealthy, the government, the church and more. Mr. Barnes called it "a baroque comedy," according to The Times.

A 1972 film version, for which the playwright penned his screenplay, starred Peter O'Toole. The dark comedy focuses on an heir to a title who believes he is Jesus Christ. Frantic and comic, the work includes people bursting into song. O'Toole was Academy Award-nominated for it.

Mr. Barnes' mordant dark comedy Red Noses concerns a band of traveling clowns working during The Plague in medieval times. It won him a 1994 Olivier Award for Best Play.

Changing gears into the world of picturesque romance, Mr. Barnes wrote the screenplay to "Enchanted April." He was Oscar-nommed for the chore.

The words "black comedy" were often used to describe Mr. Barnes' work, and he attempted to challenge naturalism and complacency in the theatre. He once wrote, "The theatre is a thermometer of life but our theatre is a theatre without size or daring; a theatre without communion. It contains no miracles. The bread is never changed into flesh or the wine into blood. It is a theatre of carpet-slippers...

"To strike out, to launch repeated bayonet attacks on naturalism, to write rigorously against the prevailing mode, requires courage...

"A writer who does not write corrupts the soul. Besides, it is absurd to sit around sniffing wild flowers when you can invent them, and new worlds."

Among his other plays are Laughter, about Auschwitz and Ivan the Terrible; The Bewitched, about The Inquisition; and Leonardo's Last Supper, a musical comedy about Leonardo da Vinci's undertakers.

Each of the above titles has been billed as a "dark comedy." Mr. Barnes once wrote, "'I believe the only thing in the theatre that has a ring of truth is comedy."

Survivors include his wife, Christie Horn Barnes, their daughter Leela, 4, and their triplets, Abigail, Zachary and Nathaniel, 19 months old, according to The Times.