Kate and William join sombre royals to pay tribute to the Duke of Westminster at memorial service at Chester Cathedral

NEW The 25-year-old seventh Duke of Westminster (right) led hundreds of mourners as they gathered to pay tribute to his father, the sixth Duke of Westminster (insert), at Chester Cathedral today. Billionaire Gerald Cavendish Grosvenor, a close friend of the Royal Family, died of a heart attack aged 64 on August 9. The father-of-four was Britain's third richest man and the richest property developer in the UK, whose vast wealth came from estates in Oxford, Cheshire, and Scotland as well as huge swathes of Mayfair and Belgravia.