Was Shakespeare the love child of Queen Elizabeth?

Theories abound as to the true identity of William Shakespeare, but a new book makes the most scandalous suggestion yet - that the creator of Hamlet and Macbeth was the illegitimate son of Queen Elizabeth I.

In Oxford: Son of Queen Elizabeth I, Paul Streitz, an American writer, makes the sensational claim that Elizabeth I produced several children, overturning accepted notions of the Virgin Queen. He further argues that the first child, secretly sired in 1548, was raised as Edward de Vere, 17th Earl of Oxford - who is one of the main claimants to the name of Shakespeare for those who do not believe a lad from rural Warwickshire capable of literary genius.

"I have rewritten Elizabethan history," Streitz claimed from America yesterday, prior to visiting Britain next week to lecture. "The Virgin Queen was a myth created by the Tudor propaganda machine that was copied uncritically by the vast majority of historians in the following centuries." He rejects this, acknowledging that academics will be "gobsmacked" by his audacity. "It's like the Rosetta Stone or The Origin of the Species where everything is suddenly different. You look at it from a completely different perspective."

Streitz, an author of plays and musicals, became a passionate supporter of the Oxford theory about Shakespeare's true identity when he was researching a play. His book, which is already published in America, began as an attempt "not to argue the case but rather to write a story of the development of the artist Oxford", he said. "To do that, I knew that he was brought up in court in England from the age of 14, so I started reading a lot of biographies of Elizabeth I to understand her and to understand life in the Elizabethan court."

Biographers readily acknowledge that there was some kind of romance between the teenage Elizabeth and Thomas Seymour, an ambitious courtier whom she had earlier refused to wed. But they conclude that nothing of consequence happened between them, despite accounts by staff that he visited her chamber in a state of undress and claims of gross impropriety.

Heavyweight academic study by the likes of David Starkey supports the notion of the Virgin Queen, but Streitz, though an amateur historian, has grown to doubt this.

He argues that, after the alleged romance, Elizabeth disappeared at a time when she would have been expected to be with her beloved and pregnant stepmother, Katherine Parr. Historians of the period say Elizabeth was sick, yet there were no records of doctors seeing her until much later in 1548. "I became suspicious that she had had a child," Streitz said. "And if you start studying the literature, there were rumours coming directly from Elizabeth that she had had a child."

In a letter, she discusses and condemns rumours of her "lewd demeanour" but Streitz suggests she protests too much.

"She does not say the rumours are false; rather, she says the rumours are damaging to the king's majesty's sisters," he said.

But what happened to this alleged child? Streitz argues he was placed in a safe home - with nobleman John de Vere, the 16th Earl of Oxford, who was forced into a marriage with a woman close to Elizabeth's advisers against his own wishes to provide that haven.

There are no christening records to indicate the birth of an Edward de Vere. But his education was overseen by people in high places. And when he became a ward of the Crown, after his father's death, the wardship was not sold on by the Crown for cash, even though that was the practice.

This meant Queen Elizabeth had the right to determine who Oxford would marry. Streitz further argues that Oxford clearly knew of his origins and reflected them in works such as Hamlet and the Sonnets.

Paul Streitz will speak at the Institute of Historical Research, University of London, Malet Street, WC1 on Tuesday at 6.30pm; free