The ford sits roughly 500 metres to the northwest of Knocknanuss Hill, and it is here, according to local tradition recorded by Bowman in 1934, that Sir Alexander Mac Donnell met his death during the Battle of Knocknanuss in 1647. That a crossing point on a modest river should be named for the man allegedly killed at it, and that the name should have survived long enough to appear on the Ordnance Survey's six-inch map of 1842, says something about how deeply the battle lodged itself in local memory.

The Battle of Knocknanuss was one of the bloodiest engagements of the Confederate Ireland period, fought between the Confederate Catholic forces and a Parliamentarian army under Lord Inchiquin. The Confederates, a coalition of Irish Catholic landowners and clergy who had formed their own government during the upheavals of the 1640s, suffered a decisive defeat. Mac Donnell, who served as second in command of the Confederate Army, was killed during the fighting. The precise location of his death at this ford rather than on the hill itself suggests the retreat, or a flanking movement, carried the action down to the river. It is worth noting that the 1842 OS map places a feature called Chieftain's Ford somewhat further south along the Awbeg, approximately 1.1 kilometres to the south-southwest, on the boundary between the townlands of Rathmaher and Lackaleigh, which raises the possibility that the name migrated in local usage, or that more than one crossing became associated with the battle over time.