It is a leacht cuimhne, an Irish memorial monument, and it commemorates a single man: Captain Anthony O Flaherty, as named on two plaques set into the northeast face of the structure, both dated 1822.

The monument stands in Cill Éinne, the village at the island's eastern end whose name translates roughly as the church of Éinne, the early medieval saint closely associated with Aran. The O Flahertys were one of the great Connacht dynasties, their name inseparable from the history of the west of Ireland across many centuries, and a captain of that name dying in 1822 would have lived through a period of considerable upheaval, from the aftermath of the 1798 rebellion through the Napoleonic era and into the early decades of the nineteenth century. The structure itself is compact, measuring just 1.1 metres in length and 0.9 metres in width, but its near-two-metre height and the deliberate placement of the cross and inscribed plaques give it a presence well beyond its footprint. Mortared rather than dry-built, it represents a more formal tradition of commemoration than the simple field cairns the term leacht can sometimes describe.