One of them, the more northeasterly of the pair, sits within the area recorded as the "Battlefield", a quiet designation for ground that witnessed one of the most consequential engagements of the 1798 rebellion. When someone came to look for it in 1976, there was no visible surface trace at all.

The battle in question took place on 8th September 1798 at Ballinamuck, a name that translates roughly as "the mouth of the pig". It was the site where the combined French and Irish rebel force, which had landed at Killala Bay in County Mayo under the French General Humbert and marched east in a brief, improbable campaign, was finally cornered and crushed by Crown forces. For the French troops, who surrendered as prisoners of war, the outcome was humiliation but survival. For the Irish rebels who fought alongside them, it was a massacre. The graves at Shanmullagh almost certainly belong to some of those who died there, though the cartographic record is the only surviving marker of their location. By the time the OS surveyors noted them in the early twentieth century, the graves were already old enough to be curiosities rather than tended memorials.

What makes this particular burial so quietly unsettling is the gap between its legibility on paper and its absence on the ground. A map can hold a name long after the earth has closed over any physical evidence, and this spot demonstrates that precisely. The soldiers buried here, whoever they were, exist now only as a notation on a surveyed plan and as a coordinate in an archaeological record that itself confirms there is nothing left to see.