It is not much to look at now, but that hollow is almost certainly the work of unauthorised digging, and what was disturbed may have been the grave of a medieval nobleman whose death helped shape the turbulent politics of fourteenth-century Connacht.

As recently as 1943, the spot was recorded as a small grassy mound beneath a thorn tree. Long before that, local tradition held it to be the resting place of Edmund de Burgo, son of William Óg de Burgo, the Red Earl of Ulster, one of the most powerful Anglo-Norman magnates in Ireland. In 1338, Edmund was abducted and killed by members of the de Staunton family. The murder was not an isolated act of violence but part of the broader fragmentation of de Burgo power that followed the assassination of the Red Earl's grandson, William Donn, in the same period, a collapse that effectively ended the earldom of Ulster as a functioning Anglo-Norman institution for generations. Whether Edmund was buried on the island in haste, in secrecy, or with some ceremony, the tradition placing his grave at this remote spot on Lough Mask is old enough to have been treated as established local knowledge by the mid-twentieth century. The mound, modest as it was, carried enough significance that someone at some point decided to dig into it, leaving only the depression that remains today.