Author Henry Hitchings explores the lives and works of Britain's radical and pioneering 18th-century novelists who, in just 80 years, established all the literary genres we recognise today. It was a golden age of creativity led by Daniel Defoe, Jonathan Swift, Henry Fielding, Laurence Sterne, Fanny Burney and William Godwin, amongst others. Robinson Crusoe, Gulliver's Travels, Tom Jones and Tristram Shandy are novels that still sparkle with audacity and innovation. On his journey through 18th-century fiction, Hitchings reveals how the novel was more than mere entertainment, it was also a subversive hand-grenade that would change British society for the better. He travels from the homes of Britain's great and good to its lowliest prisons, meeting contemporary writers like Martin Amis, Will Self, Tom McCarthy and Jenny Uglow on the way.

Hundreds of years ago in faraway Iceland the Vikings began to write down dozens of stories called sagas - sweeping narratives based on real people and real events. But as Oxford University's Janina Ramirez discovers, these sagas are not just great works of art, they are also priceless historical documents which bring to life the Viking world. Dr Ramirez travels across glaciers and through the lava fields of Iceland to the far north west of the country to find out about one of the most compelling of these stories - the Laxdaela Saga.

Julien Temple's epic time-travelling voyage to the heart of his hometown. From musicians, writers and artists to dangerous thinkers, political radicals and above all ordinary people, this is the story of London's immigrants, its bohemians and how together they changed the city forever. Reaching back to the dawn of film in London at the start of the 20th century, the story unfolds through film archive, voices of Londoners past and present and the flow of popular music across the century; a stream of urban consciousness, like the river which flows through its heart. It ends now, as London prepares to welcome the world to the 2012 Olympics.

Intrepid adventurer Michael Palin travels through Pakistan's North-West Frontier Province, starting on the Khyber Pass and ending five miles from K2 on the Pakistan/China border. He passes through Darra, visits a street dentist in Peshawar, goes bull racing with a Pakistani aristocrat and is almost trampled to death, and finally crosses over the Lowari Pass into the buffer state of Chitral.

Travelling from the unique Muslim contribution in the medieval south, Andrew Graham-Dixon immerses himself in true Spanish culture and meets the people who live and work with this artistic legacy. He looks at Muslim political and cultural influence as he travels from Cordoba to Granada, seeing classic buildings such as the Great Mosque in Cordoba, the Alcazar in Seville and the Alhambra in Granada. He also shows how the Moors introduced new foods – including citrus fruits, coffee and spices

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. In search of answers, Horizon travels round the globe, from the remotest inhabited island to the polluted centres of California and the UK. We meet sufferers and the scientists who have dedicated their lives trying to answer the mystery of why we are becoming allergic to our world.