Writer Simon Nye's most successful TV series in the '90s was Men Behaving Badly, so for him to go back to a time when, after years of Puritan rule under Cromwell, people were suddenly free to behave 'badly' under Charles II—and, if this play is to be believed, they took full advantage of this—seems appropriate.
Because, while the details may be made up, the actual story is completely true. There really was an Irishman called Colonel Thomas Blood who, in 1671, attempted to steal the Crown Jewels (remade after the Restoration for Charles's coronation), which really were kept in a cupboard in the Tower of London watched over only by 77-year-old Talbot Edwards, who would show them to anyone who asked to see them.
Blood carried out the robbery dressed as a priest alongside an actress playing his wife. He escaped with several items, including the Imperial State Crown, but he and his crew were captured beside the Thames. What happened to him after he was caught is perhaps surprising, after he made a personal appeal to the King.
Al Murray dominates the production as both the sex-loving King Charles and ex-soldier Talbot Edwards, and with both he has plenty of banter, some of which seems genuinely improvised with non-faked corpsing, with Mel Giedroyc as a French Noblewoman—who comes out to chat with the audience at one point and even sits on someone's knee—and as Mrs Edwards, who sees the potential for merchandising with Crown Jewels-themed gifts and baked goods.
Carrie Hope Fletcher also bridges both households, as Charles's Lady of the Bedchamber, opening with a rousing number in praise of her monarch and ending the show with another belter of a song (composer is Grant Olding) dressed as Britannia, and as the Edwards's daughter Elizabeth, whom the parents are desperate to marry off to get rid of her while doting on their son, absent fighting overseas.
Aidan McArdle's Colonel Blood is the intelligent one of the rebels, with his intricate plotting and his conviction that this is all for the glory of Ireland—until modifying his viewpoint might help his chances of surviving (still a common approach in politics). With him are Joe Thomas as his not-too-bright son Tom Blood Jnr, Neil Morrissey—one of Nye's former badly-behaving men—as militant Captain Perrot and Tanvi Virmani as actress Jenny Blaine, co-opted to pretend to be Blood Snr's wife, but she doesn't believe that this realism is proper acting so engages in histrionics and the occasional dance in the Edwards's parlour.
Sean Foley's production is full of great moments and set pieces, with some of his distinctive style showing through in little touches, like the footman changing the set who always flashes a cheesy grin at the audience as he passes, and the giant map of the Tower that is suddenly animated with little model people, seen from above, chasing one another through the maze of corridors. However, it does lack the continuous momentum of a heist movie or, for that matter, of a half-hour sitcom as the plot is fairly trivial and is treated as such, and it is pretty long for a comedy at more than 2½ hours—although I'm guessing that may vary quite a bit between performances.
Where it shines is in that comic banter and in Murray's monologues with the audience, especially in act 1 when the lights come up in the auditorium and he does the comedian's "what do you do" routine but as an arrogant King Charles II. It is very satisfying for the audience that some of what comes out in those conversations is referred to again much later, and not just by him, but by Giedroyc and Morrissey as well.
While it tells an amazing true story from our history, this is probably best regarded as an adult pantomime, creatively directed with occasional audience participation, featuring a cast of very good comedy and musical theatre performers who seem to be having a whale of a time. Which means there's a good chance that you will too.