Delivering the Shakespeare Lecture at this year's Cheltenham Festival on Saturday, Gregory suggested a potential inspiration for Shakespeare's last play, The Tempest, which it seems has gone unnoticed by scholars and editors of the plays until now.

Gregory is currently directing The Tempest, and came across the connection when he was researching the play in preparation for the new production. 

It has long been acknowledged that a letter by William Strachey describing the shipwreck of the Sea Venture off Bermuda in 1609 provided Shakespeare with details for The Tempest. What has apparently gone unnoticed is that a royal ship was not only launched much closer to home the same month that the Strachey letter arrived in London, but that its launch was nearly thwarted by bad weather. When a sudden storm in the river Thames threatened to destroy the ship, its builder assumed that his enemies, like the magician Prospero in the play, were using magical powers to create the tempest, and wreck the ship. 

The ship, the Prince Royal, the most significant ship to be built in the entire reign of James I, was dedicated to the king's son, Prince Henry, who had just been made Prince of Wales. Large crowds turned out to see the ship being built and to watch the launch on 25 September 1610. The ship builder, Phineas Pett (pictured), wrote a journal in which he describes the launch and his suspicions that his enemies had summoned up the storm to wreck the ship. 

Shakespeare probably wrote The Tempest for performance at either the Blackfriars Theatre or the Globe in the summer of 1611, and its first recorded performance at court took place on 1 November that year.

Gregory said: "When I read Pett's journal the connection seemed obvious to me. In The Tempest, the King's ship is apparently wrecked when Prospero summons up his spirits to attack the ship as it passes his island."

Professor James Shapiro, the Shakespeare scholar and author of 1599, and the recent 1606, thinks Gregory has stumbled across a piece of source material unnoticed by editors and scholars, and believes the connection to be a very exciting new piece in the Shakespeare jigsaw, and a significant finding in Shakespeare's 400th anniversary year.