The Battle of Ballynahinch is fought outside Ballynahinch, County Down, on June 12, 1798, during the Irish Rebellion of 1798 between British forces led by Major-General George Nugent and the local United Irishmen led by Henry Munro.
Munro is a Lisburn linen merchant and Presbyterian United Irishman who has no military experience but has taken over command of the Down organisation following the arrest on June 5 of the designated leader, Rev. William Steel Dickson. Upon hearing of the victory at Saintfield on June 9, Munro joins the rebel camp there and then moves to Ednavady Hill, Ballynahinch to join the thousands who have gathered in support of the rebellion. The response of the British garrisons is to converge on Ballynahinch from Belfast and Downpatrick in two columns accompanied by several pieces of cannon.
The battle begins on the night of June 12 when two hills to the left and right of Ballynahinch are occupied by the British who pound the town with their cannon. During a pause when night falls, some rebel officers are said to have pressed Munro for a night attack but he refuses on the grounds that it is unchivalrous. As a consequence many disillusioned rebels slip away during the night.
As dawn breaks the battle recommences with the rebels attacked from two sides and although achieving some initial success, confusion in the rebel army sees the United Irishmen retreat in chaos, pursued by regrouping British forces who quickly take advantage by turning retreat into massacre. Initial reports claim four hundred rebels are killed, while British losses are around forty.
Munro escapes the field of battle but is betrayed by a farmer who he has paid to conceal him and is hanged in front of his own house in Lisburn on June 16. Ballynahinch is sacked by the victorious military after the battle with sixty-three houses being burned down. Cavalry scours the surrounding countryside for rebels, raiding homes and killing indiscriminately, the 22nd Dragoons being guilty of some of the worst atrocities. The most famous victim is Betsy Gray, a young female rebel who, with her two brothers, is slaughtered in the post-battle massacre, ensuring her place in legend to this day.