Battle of Knockavoe Battlefield

The Battle of Knockavoe was fought in 1522 between the O'Donnells, led by Hugh Dubh O'Donnell and Manus O'Donnell, both sons of Sir Hugh Dubh O'Donnell, against the O'Neills, in which the O'Neills and their supporters were surprised and routed. Knockavoe was not a lost pitched battle, rather it was in fact the result of a nighttime surprise attack on the O'Neill camp by the O'Donnells.

Knockavoe is the hill just behind Strabane in County Tyrone.

Source: Wikipedia