When a rebellion spearheaded by the United Irishmen broke out against British rule in Ireland, rebel forces led by John Esmonde made plans to capture Prosperous.

[1] Esmonde had 200 rebels under his command, while Prosperous was garrisoned by elements of the Royal Cork City Militia under the command of Captain Richard Swayne reinforced by detachments of a Welsh mounted fencible regiment, the Ancient British Regiment of Fencible Cavalry Dragoons (also known as the Ancient Britons), numbering 150 men in all.

The barracks were quickly surrounded and attacked by the rebels who repulsed an attempt by the garrison to break out; "Swayne himself was surprised in bed, shot and piked to death and his body burned in a tar barrel.

"[3] The remainder of the garrison were trapped in the upper floors of the barracks which was set on fire by the rebels, causing them to jump in desperation onto the ground below, where they were summarily executed with pikes.

Prosperous remained under the control of the United Irishmen until 19 June, when a detachment of the 5th Dragoon Guards under the command of Lieutenant-Colonel Stewart recaptured the town.