3rd Tipperary Brigade The 3rd Tipperary Brigade was one of approximately 80 such units that constituted the Irish Republican Army since the time of their formation from the Irish Volunteers , until after the Civil War . The Brigade was based in southern Tipperary and conducted its activities mainly in mid - Munster . Establishment . The core of the unit from its earliest existence was the group known as ' The Big Four ' . These were Seán Treacy , Dan Breen , Séamus Robinson and Seán Hogan . War of Independence . The 3rd Tipperary Brigade was one of the most active during the War of Independence . The ambush led by Treacy , Robinson and Breen at Soloheadbeg is generally acknowledged as the opening engagement of that war . Two members of the Royal Irish Constabulary , James McDonnell and Patrick O ' Connell were killed in the attack . Breen has left apparently conflicting accounts of their intentions that day . One implies that the purpose of the confrontation was merely to capture explosives and detonators being escorted to a nearby quarry . The other , that the group intended killing the police escort to provoke a military response . " Treacy had stated to me that the only way of starting a war was to kill someone , and we wanted to start a war , so we intended to kill some of the police whom we looked upon as the foremost and most important branch of the enemy forces . . . The only regret that we had following the ambush was that there were only two policemen in it , instead of the six we had expected . " Civil War . Reservations about the Treaty caused division within the Brigade . Some members sided with the Provisional Government , ( later the Irish Free State ) , while others remained neutral during the ensuing Civil War . The majority , including flying column commander Dinny Lacey and Seumas Robinson , took the Republican side . Lacey was killed in action against Free State troops in 1923 in the Glen of Aherlow while Robinson was a General throughout the civil war . On - line sources . Ó Duibhir : " The Tipperary Volunteers in 1916 : A Personal Account 75 Years On " : from County Tipperary Historical Society : THJ : 1991 Brendan A . Creaner : The Rescue at Knocklong ( 8 December 2003 ) Lt Col . T . Ryan : ( a ) : " One Man ' s Flying Column Part I " : THJ : 1991 Ryan : . . . ( b ) : " One Man ' s Flying Column ; Part II " : THJ : 1992 Colmcille : ( a ) : The Third Tipperary Brigade ( 1921 – 1923 ) ; Part I - " From Truce to Civil War " : THJ : 1990 Colmcille : ( b ) : The Third Tipperary Brigade ( 1921 – 1923 ) ; Part II - " From Ambushes to Executions " : THJ : 1991 Colmcille : ( c ) : The Third Tipperary Brigade ( 1921 – 1923 ) ; Part III - " The End of the Civil War " : THJ : 1992 Bibliography . Breen , Dan : " My Fight for Irish Freedom " : 1926 : ISBN 978 - 0 - 900068 - 34 - 8 Ryan , Desmond : " Sean Treacy and the 3rd . Tipperary Brigade " : The Kerryman Limited , 1945 Augusteijn , Joost " From Public Defiance to Guerrilla Warfare " : 1996 : ISBN 978 - 0 - 7165 - 2607 - 0 Shelley , John R . " A Short History of the 3rd Tipperary Brigade " Published by ( Phoenix ) : 1996 South Tipperary Brigade " Poblacht na h - Éireann . Proclamation ( explaining the Reasons why the Brigade Feel Impelled to Take Up Arms Against the Government ) " : 1923 Berresford Ellis , Peter : " Eyewitness to Irish History " : ISBN 978 - 0 - 470 - 05312 - 6