Diana Taj Mahal photo captured disintegrating marriage

It was a photograph that captured a disintegrating marriage. A princess without her prince.

Prince Charles had promised - during a visit to Agra when a bachelor - to bring his bride to this romantic monument.

Instead, in 1992, he met business leaders, made two speeches and launched a new charity. She sat in isolation on a bench in front of the Taj Mahal.

Diana, Princess of Wales - who understood the power of imagery - said it had been a very healing experience. Asked what she meant, the princess replied: "Work it out for yourself."

Diana is a name that continues to resonate in India.

Twenty-four years on from his mother's visit, Prince William will bring his wife to marvel at the mausoleum that is made of marble, jade and other precious stones.

One Bengal poet has described it as a "teardrop on the face of eternity".