Another gravestone of interest [in the churchyard at Llansantffraid-Yn-Mechain] is the one on moulded pillars at the east end of the church, and was pointed out to us as being the stone marking the resting-place of the body of “David Maurice, the Suicide.” Tradition is a little at fault, as this is not the grave; but, for all that, Maurice or Morris may have been buried here in preference (under the circumstance) to the family vault at Llansilin. (...) The story touching David Maurice’s grave is that the entombed committed suicide in the river Tannatt, near to his father’s house, Penybont or Glan Cynlleth. The pool till lately was called “Llyn Dafydd Morris.”
Tradition asserts that D. Maurice, of Penybont, caused the “Carreg y big,” or “stone of contention,” to be removed from the centre of Llanrhaiadr village, in consequence of the great fighting caused by the assumption of the prize-fighter of the neighbourhood of the title of “Captain,” by leaping on the stone and proclaiming himself “Captain Carreg y big.” This was carried to such a pitch that the vicar of Llanrhaiadr begged David Maurice to remove the stone, which he did with a team of oxen, and placed it in his farm-yard; when, lo! and behold! the cattle, horses, sheep, and pigs, like maddened creatures, danced and pranced about the stone, and ending their joust with horning, biting, and eventually killing each other at the shrine of the “stone of contention.”
David Maurice, thinking the place haunted because of the stone, caused it to be rolled into the river near at hand, thinking the “charm would be thereby broken,” but, sad to relate, one morning he himself was found drowned in the pool which was called until lately “Llyn Dafydd Morris.”
The country people look at the death of David Maurice as a just retribution because he had removed the “Carreg y big,” which was said to be a boundary stone, and should not have been disturbed. This story received general credence.
In ‘A History of the Parish of Llansantffraid-Yn-Mechain’ by Thomas Griffiths Jones, in ‘Collections, historical and archaeological, relating to Montgomeryshire’ (1868).