"Robin Goodfellow was said to be the king of the Hobs"

Soz, TomBo, I can't let that slip past without some flippant comment, but my respect for your etymological knowhow restricts my flippancy to the following:

His Highness King Rob has just contacted me via on the subject of Carreg-y-Bwci, to tell me to post this - http://www.themodernantiquarian.com/post/30263