Acclaimed war correspondent Rageh Omaar examines the effect the Crusades have on the world today. In the West, the Crusades are a chapter of Christian history that has little impact on our everyday lives, but in the Middle East many believe that the Crusades are happening again.

Leading British writer Howard Jacobson, a Jew himself, examines the origins and consequences of Christian belief. He argues that although Christianity originated in devout Judaism, for Jews it has been, for the most part, a calamity.

The world is affected by an obesity epidemic, but why is it that not everyone is succumbing? Medical science has been obsessed with this subject and is coming up with some unexpected answers. As it turns out, it is not all about exercise and diet. At the centre of this programme is a controversial overeating experiment that aims to identify exactly what it is about some people that makes it hard for them to bulk up.

Whether it’s English, Spanish, Chinese, or Urdu, babies and young children are able to pick up their native language with remarkable ease; no one language seems any more difficult than any other. Yet few children who are taught a language in school have anything to show for it when they grow up. Why is learning a second or third language so difficult?

This World has gained rare access to Nelson Mandela, after years of retirement from public life.

In a special one-hour edition of the Money Programme, Fiona Bruce presents the definitive profile of Bill Gates as he embarks on his latest challenge - giving away the billions he has amassed, through the charitable foundation he runs with his wife and his father.

Extraordinary photography reveals the incredible swarm intelligence that lies behind animal invasions.

Jon Blair's Oscar-winning documentary is the first ever eye-witness account of the life and legacy of the iconic child diarist, Anne Frank.

Documentary which tells the story of evolution theory since Darwin postulated it in 1859 in 'On the Origin of Species'.

At least 34 teenagers were stabbed to death last year in the UK. In just a decade, the number sentenced for carrying a knife has risen ten-fold. So why are so many of Britain's youngsters arming themselves with knives? And why do some kill?

Frank Skinner is one of Britain's most controversial comedians but even he felt the comments broadcast last year by Jonathan Ross and Russell Brand on BBC Radio went too far. As he experiments with reducing the expletive count in his own stand-up show, Frank sets out to discover if the Ross-Brand storm really was a watershed in broadcasting's debate about bad language and offence.

Jeremy Vine reveals the problem of sexual bullying in our schools and hears from experts, parents and teachers - but most importantly from the kids themselves - on what we can do to tackle it.

This moving film reveals the differing fortunes of a mother polar bear and a mother grizzly bear, and their new-born cubs, in a rapidly-changing world. The shrinking Arctic ice may be making life much tougher for polar bears, but it is offering new opportunities for grizzly bears to the south.

Tiger experts in Bangladesh have a problem: how can they encourage local people to protect the beautiful and endangered Bengal Tiger when these animals have developed a taste for human flesh?

Mark Meakin attempts to unravel the mysterious wanderings of the biggest fish in the sea.

Just how does the cuckoo trick other birds into accepting its eggs and raising its young? In this film, new photography is combined with archive footage and the latest scientific findings to solve a puzzle which, as narrator David Attenborough explains, has perplexed nature-watchers for thousands of years.

Coverage of President Obama's Inauguration, with Huw Edwards and Matt Frei in Washington.

Clive Myrie traces the life story of Barack Obama, America's first black president.From Obama's broken home childhood in Hawaii, through his political awakening in the rough neighbourhoods of Chicago, to his arrival in Washington, Myrie follows the extraordinary journey that transformed the son of a Kenyan student into the most powerful man in the world.

Jonathan Dimbleby explores ten thousand miles of one of the world's most awe-inspiring countries. Summer 2006. Having lived through the Cold War, Jonathan makes his first stop in the city of Murmansk, which stands as a reminder to the years when England and Russia were close allies in a war of survival against the Nazis.

The unexpected marriage of high-tech glamour with the gritty reality of 1970s Northern Ireland captured the public's imagination but this early optimism would end in failure. Although the cars looked great, the windows leaked and the engines seized; as his financial problems mounted the maverick DeLorean faced charges of drugs trafficking. Adrian Dunbar narrates the story.

Jimmy Doherty, pig farmer, one-time scientist and poster-boy for sustainable food production is on a mission to find out if GM crops really can feed the world.

We are in the grip of an allergy epidemic. 50 years ago one in 30 were affected, but in Britain today it is closer to one in three. Why this should be is one of modern medicine's greatest puzzles.

Margo MacDonald, the firebrand, independent politician, is one of Scotland's most popular public figures. But she also has Parkinson's Disease and, earlier this year, she spoke openly of her desire to choose the moment of her death. Now, in this deeply personal film, she uncovers the truth about assisted dying, meeting those with illnesses like hers who are desperate to die, and exploring how British law could be changed to allow them to choose when they can.

Following on from the BAFTA-shortlisted Panorama programme Taking on The Taliban, Ben Anderson catches up with 24-year-old Lance Corporal Jack Mizon of the Queen's Company, Grenadier Guards.

Controversial celebrities of the 20th century. Jazz singer Billie Holiday is remembered today for her turbulent personal life as much as for her artistic achievements - addicted to drink, drugs and abusive men, the enduring image is of a tragic victim. However, archive footage and interviews with friends reveal a different Lady Day - a strong woman, determined to satisfy her voracious appetite for sex, drugs and music.

Cork producer and wildlife enthusiast Francisco Garrett explains what will be lost if cork stoppers are replaced by plastic or screwtops.

Louis Theroux joins the Philadelphia Police Department patrolling the most dangerous part of one of the most violent cities in America.

One of two contrasting views on immigration under the slot title 'Unwelcome Britain?'. The other is 'Immigration is a Time Bomb'

Short series of biographical films showing the debt Britons owes to pioneers of multi-racial Britain. Mary Seacole was an accomplished Jamaican nurse who, on deciding to help during the Crimean War, had to travel there at her own expense and risk because Florence Nightingale's organisation rejected her for being 'too dark'. One there, she saved the lives of thousands of British soldiers.

As the world swaps theories on global warming, Five Disasters Waiting To Happen looks at how some of the world's leading cities are dealing with the practical reality of climate change.