The claim is being made by Dr Eric Sams, who wrote the account of Shakespeare's first 30 years, The Real Shakespeare, which portrayed the playwright as a farmer, as well as a glover and wool-dealer.
Dr Sams' latest study, Shakespeare's Edward III: An Early Play Restored to the Canon, argues that the dramatisation of Edward III's invasion of France and assault on the Countess of Salisbury's virtue was wholly written by Shakespeare - not partially, as is usually suggested.
Academics have claimed that while Shakespeare may be the author of the second act of the play, the remaining four are by another, lesser, hand. As a result it was excluded from the influential Complete Works edited by Professor Stanley Wells for Oxford University Press.
Dr Sams argues, in the book to be published by Yale University Press on 22 August, that Shakespeare wrote acts I, III, IV and V of the play in about 1589 - at the end of his so-called "lost years" between 18 and 28 - before publishing his "first" play, Titus Andronicus, in 1594. In the early 1590s, he came back to Edward III, rewriting the second act and infusing it with the poetry of his sonnets.
It is particularly apt to bring forward the theory now, Dr Sams says, because this year marks the quatercentenary of the play's original publication. Other plays accepted into Shakespeare's canon after the First Folio in 1623 are Pericles, and his late play, The Two Noble Kinsmen.
"The established view is that Shakespeare wrote almost nothing until he was 28, when he began writing on an accomplished level, which strikes me as ludicrous," Dr Sams said yesterday.
"It is like saying Mozart wrote nothing until he was 30, then he wrote Don Giovanni. The fact is that he went to London aged 18, with a wife and son to support, and needed money. I have no doubt that he wrote plays during that period and that Edward III was one of them."
Dr Sams charts numerous echoes between the play and Shakespeare's canon, particularly the sonnets. Phrases like "their scarlet ornaments" and "lilies that fester smell far worse than weeds" occur in both.
Other parallels include the number of new words contained in the play - as in every accepted Shakespeare work - including "cleftures", "bed- blotting", "snaily", "hugey" and "death-procuring". Dr Sams also cites numerous words used in Edward III that are peculiar to Shakespeare, or of which he is the first known user, such as "beguile"; "clangour" and "rash" (operating quickly).
The reason that such a claim for Edward III has not been made before, he says, it is that it is too contentious. "Some Shakespeare scholars think the same, but they don't dare say so. Professors cannot be wrong.
"But both Professor Wells and Professor Gary Taylor, who co-edited William Shakespeare: A Textual Companion, have expressed regret they did not include Edward III in their books."
Dr Martin Wiggins, fellow of the Shakespeare Institute of the University of Birmingham, was cautious about Dr Sams' theory. "The idea that [Edward III] is wholly by Shakespeare hasn't generally found favour," he said. "Dr Sams' theory assumes that Shakespeare got better as time went on, and raises the question of when Shakespeare did write the sonnets and if he wrote them at a particular point in his career."
Shakespeare, or a play by any other pen?
Four extracts from Edward III:
Countess: For where the golden ore doth buried lie
The ground undecked with nature's tapestry
Seems barren, sere, unfertile, fruitless, dry
And where the upper turf of earth doth boast
His pride, perfumes and parti-coloured cost
Delve there and find this issue and their pride
To spring from ordure and corruption's side.
Act I Scene i
King Edward: O thou world great nurse of flattery
Why dost thou tip men's tongues with golden
And peise their deeds with weight of heavy lead
That fair performance cannot follow promise?
Act II Scene i
Warwick: Dark night seems darker by the lightning flash
Lilies that fester smell far worse than weeds
And every glory that inclines to sin
The shame is treble by the opposite.
Act II Scene i
King Edward: The pillars of his hearse shall be their bones
The mould that covers him, their city ashes
His knell that groaning cries of dying men
And in the stead of tapers on his tomb
An hundred fifty towers shall burning blaze
While we bewail our valiant son's decease.
Act V Scene iReuse content