(I wouldn't worry too much about the argument that we don't know exactly when Shakespeare was born. It's more accurate to say that we don't know exactly where Will Shakespeare was born. But there's very little reason to imagine that he was born on any other date that 23 April - and, as I point out in my Who Killed William Shakespeare?, the likelihood that he died on the same date as he was born is not without significance.)
Today we celebrate the birthday of one of the greatest writers who ever lived. But who, or what, are we actually celebrating?
It might seem an odd question. And yet, if the answer were all that obvious, there wouldn't be so many people out there who seem determined to "prove" that William Shakespeare, Gent., of Stratford-upon-Avon could not have written the plays that made him famous.
There isn't a shred of evidence that Shakespeare himself did not write his plays. What is lacking is a credible biography of the great man. And so I can empathise (a little) with those who struggle to match the playwriting genius with the rather innocuous figure we read about in so many books.
Of course, 23 April is also the feast day of England's patron saint (I'm tempted to put, "England's other patron saint" - you know, the one who never set foot in England). In many ways, this coincidence is part of the problem. When we celebrate Shakespeare's birthday (and his deathday) we're simultaneously celebrating St George and, by definition, everything that we think of as being essentially English. It's as if Robert Burns had succeeded in being born on St Andrew's Day. The national poet inevitably becomes slightly confused with the patron saint.
In fact, much of what we think we know (or what we think we don't know) about Shakespeare comes from a period many years after Shakespeare lived. Between 1769, when the actor-manager David Garrick hosted his farcical "Jubilee" for Shakespeare in Stratford-upon-Avon, and 1785, when Rev. James Wilmot, a clergyman who had retired to a village near Stratford, first suggested that Will Shakespeare could not have written his own plays, all our notions about Shakespeare changed.
It was during that very period that the Warwickshire lad became "the god of our Idolatry". At the same time as Will Shakespeare became a kind of national figurehead - the secular patron saint of England - we forgot who he actually was. A scholar named George Steevens whittled the known facts of Shakespeare's biography down to a few notes. We know that he was born, got married, had children, went to London, wrote some plays, and then he went home. And that's all we know.
In the process of restricting the "known" facts about Shakespeare's life to the barest minimum, a huge amount of local knowledge was rejected. Personally, I blame David Garrick and his allies: they ridiculed the people of Stratford-upon-Avon at the same time as they put Shakespeare up on a rather cheap and nasty pedestal. What the Stratford folks remembered about their town's most famous son had no place in the "new" biography of Shakespeare. Best to know nothing at all about him than to remember the facts of his life.
Two years from now, on 23 April 2016, we shall be celebrating the 400th anniversary of his death. And, frankly, I'm expecting that to be a much more interesting event. By then, we should have accessed the crypt beneath a church, 12 miles from Stratford, and had the chance to study a skull which might well be Shakespeare's. By comparing that skull with the portraits and busts of Shakespeare (including the "Wadlow" portrait, above, photographed by Chris Titmus of the Hamilton Kerr Institute), we should know for sure whether or not it is Shakespeare's skull. If it is, then we will know a great deal more about him - and especially how he died.
(I will also have published a new biography of Sir William Davenant, the poet laureate - born in 1606 - who claimed to be "the son of Shakespeare". Unsurprisingly, Davenant's reputation took a dive at the same time as the revamped, reduced biography of Shakespeare was taking root.)
All that in itself will cause many problems. The Shakespeare we are taught at school, the Shakespeare who is written about in so many books, is still the Shakespeare who was invented in the late 18th century. Not the man of Stratford, but a national ideal: essentially, a myth. And a political one at that.
So I would like to suggest that today we celebrate the make-believe Shakespeare (the one we know so little about). At the same time, we should look forward. This could be one of the most exciting and intriguing periods in Shakespeare research. We might yet be able to rescue him from the cold, dead hand of the "official" myth, the Shakespeare "brand", which goes down well with tourists but leaves us all in the dark about him. And then we will have something to celebrate.
He was one of us - not a "demigod", as David Garrick tastelessly described him, but a truly sensitive, troubled, gifted individual. A man who knew love, pain, grief, horror, fear, and who expressed those emotions more eloquently and convincingly than any other person ever has.
Happy Birthday, Shakespeare; your time is yet to come.
Simon Andrew Stirling is the author of The King Arthur Conspiracy (The History Press, 2012) and Who Killed William Shakespeare? (The History Press, 2013). He will be talking about his work on Shakespeare at the Stratford Literary Festival, Stratford-upon-Avon, on Tuesday 29 April.