Diwali is the Hindu festival of lights

Contemporary and traditional Indian dance and theatre will be performed at Sunday's free event where visitors can sample a range of Indian food.

More than 20,000 people attended last year's event, which marks the most important celebration of the year for Hindus, Jains and Sikhs.

The mayor said it was a chance to mark the richness and diversity of London.

Good over evil

"Diwali, the festival of light, celebrates the victory of good triumphing over evil, " said Ken Livingstone.

"It is a time to mark new beginnings and represents joy, reflection, resolution and forgiveness.

"Trafalgar Square will be transformed with lanterns, banners, candles and lighting."

The legend behind Diwali, or Deepaavali, is that Lord Rama returned to the capital of his kingdom Ayodhya after an exile of 14 years.

He came back in triumph after eliminating the demon Ravana, who had captured his wife Sita.

The victory is celebrated by firecrackers and lights.