General Thomas (Tom) Barry was one of the most prominent guerrilla leaders in the Irish Republican Army during the Irish War of Independence.

In 1920, Barry joined the 3rd (West) Cork Brigade of the Irish Republican Army (IRA) which was then engaged in the Irish War of Independence (1919–1921). He was involved in brigade council meetings, was brigade-training officer, flying column commander, was consulted by IRA General Headquarters Staff (GHQ), and also participated in the formation of the IRA First Southern Division. The West Cork Brigade became famous for its discipline, efficiency and bravery, and Barry garnered a reputation as the most brilliant field commander of the war. 

On 28 November 1920, Barry’s unit ambushed and killed almost a whole platoon of British Auxiliaries at Kilmichael, County Cork. In March 1921 at Crossbarry in the same county, Barry and 104 men, divided into seven sections, broke out of an encirclement of 1,200 strong British force from the Essex Regiment. In total, the British Army stationed over 12,500 troops in County Cork during the conflict, while Barry’s men numbered no more than 310. Eventually, Barry’s tactics made West Cork ungovernable for the British authorities. 

“They said I was ruthless, daring, savage, blood thirsty, even heartless. The clergy called me and my comrades murderers; but the British were met with their own weapons. They had gone in the mire to destroy us and our nation and down after them we had to go.”

He died in a Cork hospital in 1980 and was survived by his wife, Leslie de Barra (née Price), whom he married in 1921 and who was the director of organisation for Cumann na mBan and later President of the Irish Red Cross. She died in 1984. 

During the negotiations that preceded the Truce that ended the war, the British had demanded that Barry be handed over to them before progress could be made on other matters. Michael Collins refused, although he afterwards jokingly told his fellow Cork men that he had been sorely tempted. Barry opposed the Anglo-Irish Treaty of 6 December 1921, because, according to him, it betrayed the Irish Republic and partitioned Ireland. He fought on the Republican side in the Irish Civil War (1922–1923) and was imprisoned by the Irish Free State after the Battle of Dublin in July 1922. Barry had voiced the opinion that, at the start of the Civil War, while the Republican side was stronger, they should have taken over Dublin and the major cities and forced a new confrontation with the British. 

In September of that year, however, he escaped from an internment camp at Gormanston in County Meath and traveled south, to take command of the anti-Treaty IRA Second Southern Division. In November 1922, he led his men in the capture of a string of towns across the province of Munster, including Carrick on Suir, Thomastown and Mullinavat, taking the Free State garrison there prisoner. However, due to a shortage of men and equipment, he was unable to hold these places, evacuating them before National Army reinforcements arrived. After this point, Barry increasingly argued with Liam Lynch, the Republican commander in chief, that the Civil War should be brought to an end, as there was no hope of victory. In March, Barry proposed to the IRA Army executive that a ceasefire should be called, but he was defeated by 6 votes to 5. The anti-treaty campaign was belatedly called off by Frank Aiken in May, after Lynch had been killed in a skirmish with Free State troops. Barry was arrested shortly before Aiken’s order to “dump arms”, on 24 May 1923.