Written by Steve Coogan and Jeff Pope, it is based on the 2013 book The King's Grave: The Search for Richard III by Philippa Langley and Michael Jones.

The Lost King received generally positive reviews from critics, although part of the film was later ruled to be defamation, and there have been critiques of its framing or veracity.

Her research shows some sources say he was buried in 1485 in the Leicester Greyfriars priory choir area, while others say his body was thrown into the River Soar.

After Greyfriars was demolished in the 1530s Reformation, Leicester mayor Robert Herrick had a shrine built in his garden around the year 1600 saying "Here lies the body of Richard III, sometime king of England."

She meets Dr Ashdown-Hill, who is publishing a genetic genealogy study on a Canadian direct descendant of Richard III's sister.

In February 2013, Taylor announces their findings to the world at a University of Leicester press conference, at which Phillippa is largely sidelined, even by Buckley.

The closing credits say the royal family's website has reinstated Richard as the rightful King of England 1483–1485, so that he is no longer regarded as a usurper.

Also appearing are: Jessica Hardwick as Bookseller, Robert Jack as Alex, John-Paul Hurley as Buckingham, Nomaan Khan as Anil, Sinead MacInnes as Hiker, Phoebe Pryce as Jo Appleby, Alasdair Hankinson as Mathew Morris, James Rottger as Richmond, Benjamin Scanlan as Raife Langley, Mahesh Patel as Foreign Dignitary (uncredited), Sharon Osdin as Buckley's PA, Glenna Morrison as Lorna, Adam Robb as Max Langley, Simon Donaldson as Graham, Kern Falconer as Ken, Violet Hughes as School Girl 1, Josie O'Brien as School Girl 2, Robert Maloney as Heckling Bar Customer (uncredited), Lukas Svoboda as Car Seller (uncredited), Iman Akhtar as Receptionist, Lati Gbaja as Shopper (uncredited).

Philippa Langley makes a cameo appearance at the end of the film as Woman Attending the Re-Burial of Richard III (uncredited).

[7] Principal photography began in April of that year,[8] and took place across a variety of locations in the Edinburgh area, including Morningside[9] and Dalkeith.

The website's consensus reads: "The movie's curiously bland compared to the remarkable real-life story it dramatizes, but Sally Hawkins' performance saves The Lost King from feeling like a royal disappointment.

[21] Kyle Smith in the Wall Street Journal praised the film saying, "As it ticks along from one small but crucial development to another, this climax is far more exciting than any part of any superhero movie I've seen in recent months".

Indeed, she formed part of the team interview panel for every single press conference connected to the King.The suggested whereabouts of the King's remains was public knowledge prior to Philippa's intervention, however, we recognise she was the positive driving force behind the decision to dig for Richard III.

[4]British archaeologist and academic Mike Pitts, who had written Digging for Richard III: The Search for the Lost King in 2015 with the team from the University of Leicester archeology department, described the film as "a misleading saga based on a farrago of untruths and omissions".

He says that by showing a "phalanx of male archaeologists and administrators, interested only in furthering their own careers at Langley's expense", the film portrays science unfairly, and in a manner that is closed to outsiders.

[32] In February 2024, Richard Taylor initiated legal action for libel against Steve Coogan, the production company Baby Cow, and the distributors Pathé, regarding his portrayal in The Lost King.

Taylor claimed his character, as played by Lee Ingleby, was depicted in a highly negative "patronising and misogynistic" manner, and that the film suggested he took credit for the discovery, which he asserted was primarily Langley's achievement.

The ruling allowed the case to proceed to a full trial, requiring Coogan, Baby Cow, and Pathé to defend the portrayal of Taylor in the film.