Battle of Farsetmore
1567 CE.
Shown on the map at 54.954°, 7.690°.
The Battle of Farsetmore was fought near Letterkenny in County Donegal, north-western Ireland, on 8 May 1567, between the O'Neill and O'Donnell Túath. Shane O'Neill, chief of the O'Neills of Tír Eoghain, was defeated by Aodh mac Maghnusa Ó Domhnaill (Hugh O'Donnell), and the O'Donnells freed themselves from O'Neill aspirations of ruling Ulster as its King.
Text from the Wikipedia article Battle of Farsetmore, licensed CC BY-SA 4.0.