Diana Scott = Grace Kelly

I've always felt that "Darling" was a retelling of the Princess Grace story, as "The Barefoot Contessa" was about Rita Hayworth.

Both Diana and Grace started as models, became actresses and had affairs with married men. Then, they each married a somewhat older European prince and, if several bios of Grace are true, suffered from being "a bird in a gilded cage".

Diana's affairs with Miles and Robert could easily mirror Grace's liasons with her married costars Gary Cooper, Ray Milland, and William Holden. As Diana tried to escape her boring life with her Prince, Grace began to bury herself with outside interests and was said to drink her troubles away at times. It is known that Grace desperately wanted to make a comeback in Hitchcock's "Marnie", but either Prince Rainier or DeGaulle (or both) blocked her path.

As they are European, I suspect Frederic Raphael and John Schlesinger got all kinds of gossip regarding HSH Grace of Monaco, and changed a few deatils. The result- Diana Scott!!