Origin of the English idiom 'a white elephant'

As I said in my previous post, the idiom a white elephant is used to mean 'something that is practically useless, though it may have cost a lot of money'. Today I'll tell you something about its origin. This idiom "comes from the story that kings of Siam gave such animals as a gift to courtiers they wished to ruin".

From Brewer's Dictionary of Phrase and Fable, first published in 1870, but later re-printed many times, the millennium edition, revised by Adrian Room (Cassell, 2000) being my favourite.