WITH weeks of programming devoted to marking the 200th anniversary of the abolition of the trans Atlantic slave trade, it was inevitable that somone would get around to questioning just how big a role William Wilberforce played in the campaign.

Five or C4 would have called it something like The Real William Wilberforce or Slavery: The Truth, but coming from the BBC and with newsreader Moira Stuart as presenter, this is a much classier affair.

Symbolically, she's freed from the shackles of sitting behind her newsreading desk to travel to three continents to find out about Wilberforce, ending up in his home city of Hull.

It's an understandably emotional journey, although she gets the tears over and done with early in the film during a trip to Ghana in West Africa to see exactly what the slave trade entailed.

Britain didn't start the slave trade but embraced the idea wholeheartedly, becoming one of the biggest slave traders. At Cape Coast Castle, she sees the places and learns about conditions in which slaves waiting to be shipped to the Caribbean were kept.

Stuart is in the place that was the centre of the British trade for 150 years. Men, women and children were kept in chains in dark, dank, airless confinement. Many suffocated or starved to death during the wait for shipment. "This is beyond depravity," she's moved to comment, before having a good cry.

She's come in search of Wilberforce and found "all my greatest fears". She's angry and in pain, she tells us. And she finds an explanation for her fear of the ocean - "now I know it's the burial place of so many of my ancestors".

Then it's on with the William Wilberforce story. He's credited with ending the slave trade, promoting a Bill in Parliament. But this only made the slave trade illegal, with slavery itself remaining in the British colonies after the Bill was passed.

Wilberforce, as someone points out, made the British feel good about slavery. He was the conscience of the nation, seen to be trying to stamp it out. Stuart hears that many others, including Africans themselves, played key roles in emancipation.

He was born into a privileged merchant family, became MP for Hull at 21 and then for the whole of Yorkshire. Stuart's inquiries involve the trivial as well as the serious when it comes to the man's appearance. "He was "just a bit over 5ft" and, looking at a portrait, Wilberforce's biographer Kevin Belmonte points out, "his nose is a bit large".

Stuart disagrees. "I think it's a friendly nose." Her whole approach is friendly. She resists doing a hatchet job on Wilberforce's reputation, merely presents an unbiased view of his achievements and his place in the scheme of things.

Religion was his driving force. He disapproved of theatre and gambling, believing slavery was a sin for which Britain had to repent. Quakers and others had already formed an abolition committee before he took up the issue, and a five-year book tour by Olaudah Equiano, a former personal slave of a royal naval officer turned author, did much to put a human face on the campaign against the slave trade.

Asked what Wilberforce did for emancipation, one person gives her a short answer: "Not a lot really".

It's a fascinating and important story well-told, with Stuart's heartfelt approach bringing home effectively the fact that the anti-slavery campaign wasn't a one-man band but the work of "countless men and women who demanded freedom and justice for all".