SHAKESPEARE did Richard III no favours. Via the stage, Will gave the last Plantagenet a hunchback and accused him both of murdering his nephews and of boiling the Duke of Clarence to death in a vat of wine.

So effective was the Shakespearean bias that his half facts and fictions have long since blurred the lines of historical truth.

And yet, for all Shakespeare did to blight Richard III, even he didn’t build a car park on his decaying corpse. That was entirely the work of Leicester City Council. Not, of course, that they were to know that the site, which has once homed a friary, would be so phenomenally significant.

Many vague and ill-advised attempts to find the final resting place of Richard III had failed by the time Philippa Langley found herself almost spiritually compelled to finish the job. While research and evidence gathering would prove important, it was intuition and a dose of gut feeling that would carry Philippa across the finish line.

As it opens, The Lost King - which lands in cinemas this week - declares itself based not simply on a true story but upon ‘her story’. It would be fair to say the result is somewhat ironically detached from total reality. Certainly, the film has ruffled feathers at Leicester University and could face legal action from at least one irked academic, who is here painted as pantomime villain.

The incomparable Sally Hawkins is Langley and does well to covey the kitchen sink turmoil of a woman trialled by life and the sense that purpose is just beyond her reach. It’s a quirk of the film that sees Henry Lloyd play her main foil as an occasionally horse backed apparition of Richard III himself.

Steve Coogan stars too as Langley’s semi-estranged husband, but also reunites behind the scenes with Philomena’s Stephen Frears and Jeff Pope. Coogan and Pope are behind the script, Frears the camera. The Lost King has neither the impetus nor power of Philomena but shares that film’s unabashed conviction in its own moral purpose.

While things build to a gently compelling climax, The Lost King never grips. It has less a ‘big screen feature’ feel than bank holiday special on the BBC. Few in the cast appear to be truly giving their all, even as Edinburgh castle gifts them a suitably regal backdrop.