The Artist as Socialite and Soldier: Rex Whistler:

"...It is often said that Evelyn Waugh based Charles Ryder of Brideshead Revisited on Rex. Certainly, it makes sense if we then see Stephen Tennant, a great friend of Rex's, as Sebastian Flyte. The differences might be that Rex's origins were far humbler than Ryder's are posited to be, and his art less easel-based than one gathers Ryder's is. Rex wasn't nearly rich enough (though successful), nor classy enough (his father was a builder and his grandfather - appropriately - a painter and decorator) to be a serious contender in the marriage stakes he observed around him.

Rex was almost a professional Bright Young Thing. He was bosom friends with Cecil Beaton, who more perfectly fits that bill. Beaton's photograph of Rex and various others as Fragonard shepherds on a classical bridge is fabulously gaudy and gleamy, but camp beyond measure. But even as he hung out with high-born figures, he must have felt the precariousness of his position. He had a relationship with Penelope Dudley-Ward, the daughter of the Prince of Wales' "friend". But he seems to have been seriously scorched by his feelings for Lady Caroline Paget..."