However, by the time Duff's column arrived in Monasterevin in County Kildare, at 7.00 a.m. on 29 May, the bulk of the rebel forces had already accepted a government amnesty from Generals Gerard Lake and Ralph Dundas, following their defeat at the battle of Kilcullen and had surrendered at Knockaulin Hill, several kilometres to the east of the Curragh on 27 May.

[citation needed] Duff's force had by now grown to 700 militia, dragoons and yeomanry with four pieces of artillery (three having been presumably left at Monasterevin).

The designated place of surrender, the ancient fort of Gibbet Rath, was a wide expanse of plain with little or no cover for several kilometres around but neither the rebels nor Duff's force had seemingly any reason to fear treachery as a separate peaceful surrender to General Dundas at Knockaulin Hill, who was accompanied only by two dragoons, had been successfully accomplished without bloodshed.

By the time of Duff's arrival at Gibbet Rath on the morning of 29 May, an army of between 1,000 and 2,000 rebels was waiting to surrender in return for the promised amnesty.

However, Duff redrafted his own official report of the engagement before submission to Dublin Castle, his final draft was transmitted without references to his knowledge of the surrender preparations.

"[2]General Duff received no censure for the massacre and, upon his arrival in Dublin the following day, was feted as a hero by the population who honoured him with a victory parade.