LONDON -- Prince Rupert Loewenstein, an aristocrat who helped make the Rolling Stones as rich as kings, has died. He was 80.

Friend Hugo Vickers says Loewenstein, the band's former business manager, died Tuesday in a London hospital.

The Oxford-educated German aristocrat -- full name Prince Rupert Ludwig Ferdinand zu Loewenstein-Wertheim-Freudenberg -- advised the Stones for almost four decades from 1968. He masterminded their transformation from a financially rackety rock group to a formidable money-making machine.

Despite the relationship, he always said he didn't like the band's music.

Last year Loewenstein published a memoir, "A Prince Among Stones." Mick Jagger was not amused, telling a newspaper, "I don't think your ex-bank manager should be discussing your financial dealings and personal information in public."

Loewenstein's funeral will be held May 30 in London.