First off, never ever declare something an important Triad if you only have two parts of it. Two parts does not a triad make.
Doing such a foolish thing, I did a little celebratory rummaging online tonight and didn’t quite find the “omg-yes!” third leg of the triad but I did find this while rummaging: The Black Book of Carmarthen
PS I’d like to say that some of my names and places choices were brilliant pieces of research. I would. I suppose it’s possible that I unconsciously picked up some brilliantly perfect names and places information along the way. But I’m going to go with the fact there there’s nothing quite like dumb luck for creating unbelievable events.