The results of DNA tests on bones found by a team searching for the lost grave of Richard III are due to be released.
Last year the University of Leicester dug on the site of a city church where it was thought the king was buried.
They found a skeleton with a badly curved spine and head injuries consistent with recorded details of Richard's death in 1485.
Sources said the tests, the results of which are to be released at 10:00 GMT on Monday, had "gone down to the wire".
Richard's two-year reign signalled the end of the dynastic struggle known as the Wars of the Roses and is seen by some historians as the last act of the medieval era.
His death at Bosworth - the last English king to be killed in battle - ushered in the Tudor dynasty beginning with Henry VII.
Shakespeare then helped to make Richard notorious as one of the English language's most memorable villains.
While he remains for many historians the prime suspect for the death of his nephews - the Princes in the Tower - the skeleton's discovery has provided a golden opportunity for those seeking to restore his reputation to make their case.
Dr Phil Stone, chair of the Richard III Society, said: "This is an incredibly exciting time for anyone interested in Richard: it is simply the biggest news to hit Ricardian studies for 500 years.
"I really hope it is him. It is important, not just because it answers questions about what happened to his body but it gives us a chance to give him the solemn and respectful burial he deserves.
"And along with that, it gives us an opportunity to show the wider public what Richard was really like and remind them Shakespeare's play was fiction."
In September 2012, the university confirmed there was "strong evidence" a skeleton found beneath a council car park in the Greyfriars area of Leicester was the lost king.
The remains have been subjected to a battery of tests, including DNA, carbon dating and environmental analysis in an effort to confirm the identification.
Richard Taylor, deputy registrar of the University of Leicester, said: "It has been a privilege to have been involved in what could prove to be one of the biggest archaeological discoveries of recent times.
"The University of Leicester has played a pivotal role, not only in leading the archaeological dig but in terms of working in partnership with the city council and the Richard III Society to bring this extraordinary project to fruition.
"It is a testament to the skill of the University of Leicester's world-class archaeological team, led by Richard Buckley, along with the meticulous scientific work of university colleagues, that has led to this moment.
"There is a palpable excitement at the university for an announcement that could potentially rewrite history."