The saint in the name
St Mo Ling
Mo Ling - sometimes written Moling or Mholing - was a 7th-century Irish saint who became Bishop of Ferns and founded a monastery at St Mullins on the Barrow in south Carlow. He turns up in early Irish hagiography, in the Book of Mulling (a pocket-sized Gospel manuscript associated with him), and in a litter of place-names across south Leinster. Monamolin is one of those names. The village's Catholic church carries his patronage; the surrounding civil parish has been called after him on maps since at least the 1650s.
Monemoling, Monemolin, Monomolin
The Down Survey
Sir William Petty's Down Survey of Ireland - the great Cromwellian land mapping of the 1650s - wrote the village down as 'Monemoling'. Samuel Lewis's Topographical Dictionary of Ireland in 1837 had it as 'Monemolin'. The 1851 General Alphabetical Index of Townlands settled on 'Monomolin' before the modern spelling won out. None of that is unusual for an Irish place-name; what's unusual is how clearly the original Mo Ling shows through every version.
A landscape, not a battlefield
1798
The Wexford Rebellion of 1798 started at the Harrow on the night of 26 May and was crushed at Vinegar Hill on 21 June. Almost every road around Monamolin leads, within a few miles, to a place that matters in that story - Boolavogue and Father John Murphy's chapel to the west, Oulart Hill where the rebels routed the North Cork Militia on 27 May to the south, Ferns and Enniscorthy beyond that. Monamolin itself saw no recorded engagement, but the parish would have lost men and houses like every other in north Wexford that summer. The proper way to see the village is as one stop on a 1798 day, not on its own.