It seems like it goes back beyond the Norman Invasion, when all the French words started coming in, to the Anglo-Saxons. But I haven't made this a real project so I haven't got all the definitive details.
in other words, rare is older and they should have used it. Please Register or Log in to view the hidden image!
No, at least I don't think so. "Rare" is a French word that is only about six hundred years old. Anglo-Saxon is what we used to call "Old English" and was spoken before the Norman Invasion in 1066. It had no French influence.