Princess Diana was clearly in the hearts and minds of Englanders Wednesday as they marked the 20th anniversary of her death ... and if anyone forgot there were plenty of visuals to jog their memories.

Kensington Palace -- where Diana lived -- was festooned with banners, posters and flowers commemorating her death.

Diana died when she was only 36. Her children, Princes William and Harry, honored their mother by visiting the Kensington Palace White Garden -- which was planted in her honor.