Minister for Justice Willie O'Dea is to unveil a plaque in memory of a company of Irish soldiers that fought against overwhelming odds in the Congo over 40 years ago.
The Siege of Jadotville in December 1961 was one of the most dramatic events in the Irish army's history.
The 150 troops of "A" Company fought for three days against up to 4,000 Kataganians in the Congo town but had to surrender after they became hopelessly cut off from other UN forces.
The ceremony will take place at the army barracks in Athlone at 4.30pm with the Chief of Staff of the Defence Forces, Lieut Gen Jim Sreenan.
The ceremony is the first official recognition of the company's courage and determination in the face of extreme adversity.
The company's troops killed and wounded hundreds of the opposing Katanga Forces and held their positions until they ran out of ammunition, food and water.
But many of the soldiers, who were all handed back unharmed to the UN, felt they were viewed as cowards within the army and that the incident had been airbrushed out of military history.
It was the subject of a recently published book, Siege at Jadotvilleby journalist and former army officer Declan Power.