If a rook is under attack can it be castled into safety if neither king nor intervening spaces are attacked?  Someone just did this to me in a game and I didn't realize it was legal   It is legal, is it ?

yes it is.

doh! 

Only the king's path matters in castling, not the rook's.  So, for instance, with Black castling queenside, e8/d8/c8 must be clear of attackers; a8/b8 do not matter.

Don't feel bad about not knowing, it seldom comes up.  Korchnoi had to ask the arbiter the same question during one of his world championship matches against Karpov!

The clue is that a rook cannot be in check. It's a rook.

There, there, marvellosity, no need to be patronising... 

The key to castling is that the king must not be in (nor go through) any danger, because that would be illegal. Of course, any other piece is perfectly allowed to be under attack.

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Whoops, double post. I've never done that before. 

lol