Project Gutenberg, it is an 'On-line Reader Service'.
I found it by chance, many moons ago. I have it saved in my personal 'favourites' on my desk-top. (I will, try to add it to the bookmarks on MyBloggers in a moment [got to try and find the correct 'url' first!]).
If, you are able to locate it, search for a book entitled:
Short History of Wales
by
Sir Owen Morgan Edwards
When you locate it, skip a few chapters by going directly to page 20, it will take you to Chapter V11 - The Normans.
Browse through the next few chapters (they are 'short ones' - lol) to find the many references to your ancestral family the Clairs.
I think you'll find it intersting as well, to see what kind of 'environment' (for want of a better description), that Gilbert lived in - he observed so much of 'the making of (modern) Wales'.
Oh well, I suppose that as it is past noon (12.40pm actually) I had better get dressed - lol! There is one thing to be said about 'getting older' and that is 'time holds no relevence' - or not toooooo much anyway, lol!!!
T.T.F.N. xx