Both the internet and fy ngeiriadur have failed me with this one.
My great great great grandfather came from Wales to America, so naturally I often need to know how to say “great great great grandfather,” in Welsh. I’ve found no easy way to say it. Lately I’ve been getting by with " y taid fy nhaid" which has a sort of ring to it, but falls a generation short.
Anyone know the proper Welsh way of referring to ancestors beyond your grandfathers?
Hen, hen, hen … tadcu/taid (dw i’n credu)
We go as far as gorhendaid, which is great great grandfather, so one short for you - you’d have to say gorhendaid fy nhad, or tad fy nghorhendaid…
Is the hen, hen, hen, hen … structure not used then? I feel sure I’ve heard it and, in fact, that’s how I always refer to Hywel Dda ((winky, smiley thing))
For sure you can go hen hen hen - everyone will understand, so it works - but I never miss an opportunity to share gorhendaid (which is also, rather lovelily, the name of one of the hobbits in the extended family trees in the Lord of the Rings…:-)).
I recognize that as one of the hobbits! The answer was right under my nose…
Hat-tip for that kind of attention to Tolkien detail! 
Just read a S4C programme synopsis that used the phrase “hen fam-gu x9”!