FRONTLINE investigates the controversial theory that Edward de Vere, the 17th Earl of Oxford, a poet and intimate of Queen Elizabeth I, was, in fact, the real bard and author of the plays and sonnets of Shakespeare.

The program makes a strong case that the most celebrated writer in the English language was not the man from Stratford. Rather, 'Shakespeare' was a clever nom de plume used by Edward de Vere, a learned Elizabethan court insider, to publish his incomparable, but often politically scandalous, writings.

In charting what is known about the lives of both men - the man from Stratford and the 17th Earl of Oxford - FRONTLINE correspondent Alan Austin interviews those who have devoted their careers to the mystery and debate. FRONTLINE also travels to the halls of Westminster Abbey where Charles Vere searches for his ancestors' tombs and to the bard's haunts in Stratford where scholars discuss the meager historical record. And, excerpts of plays are performed and dissected by Oxfordians and Stratfordians alike for clues to the identity of their author.

Oxfordians say the facts of the man from Stratford's life don't square with the range of knowledge and experience reflected in Shakespeare's plays. The Shakespeare of Stratford was the son of an illiterate tradesman and there is no record that he had any schooling. He was a sometime actor, occasional real-estate investor and his death seemed to go unnoticed. His will mentions no writings and there is no evidence he ever owned a book. How do Stratfordians match the brillance of the writings with such obscurity?

"There are certain things that defy rational explanation," says Samuel Schoenbaum, Shakespeare biographer. "There is something incomprehensible about genius. Shakespeare was superhuman."

The Oxfordians maintain that the life of Edward de Vere - poet, highly educated courtier, adventurer and England's highest-ranking earl - really does fit with the extraordinary range of knowledge reflected in the work of Shakespeare.

The Oxfordian cause is now a movement, first spearheaded back in the 1960s by Charlton Ogburn, author of one of the most complete cases ever made for de Vere, The Mysterious William Shakespeare. His book made an impact and set the stage for various debates and mock trials, including one before three U.S. Supreme Court justices.

The contest, says FRONTLINE correspondent Al Austin in his summary, "comes down to this: Those who believe de Vere was Shakespeare must accept an improbable hoax as part of it, a conspiracy of silence involving among others, Queen Elizabeth herself. Those who side with the Stratford man must believe in miracles."