Today's Incarnation is a poet who established one of the great world religions: Guru Nanak, the 15th century founder of Sikhism.

Like the Buddha and Mahavira, the founder of the Jain religion, Nanak was a wanderer. He spent 25 years on the road and is said to have travelled as far as Mecca and the Himalayas. But, unlike his predecessors, when he had achieved enlightenment he returned to his homelands in the Punjab. He taught his disciples that, rather than renouncing the world and retreating from it, they must use their faith to change it from within. Nanak's 'disciplined worldliness' emphasised the importance of work and family.

He also instituted an idea which is practised in Sikh temples all over the world. Sunil Khilnani visits the Gurudwara Nanak Piao in Delhi as they serve the langar, a meal provided by volunteers to anyone who comes, regardless of status, sex or religion. Everybody eats together in an equalizing act, a dispelling of the taboos designed to protect caste boundaries.

Sunil explores the life of a man whose ideas were polemical and provocative. In announcing that "there is neither Hindu nor Muslim" Nanak wasn't proposing a harmonious blend of religions. Instead, he was rejecting other paths and creating an entirely new religion, one which now has around 30 million followers.

Producer: Jeremy Grange