1 Cork Brigade - 1 Southern Division
| Operation | County | Location | Date |
|---|---|---|---|
| Killing of 2 RIC members on tram | Cork | Lower Glanmire Road, Cork | 11 May 1920 |
| Killing of RIC Divisional Commissioner Gerald Bryce Smyth | Cork | South Mall, Cork | 17 July 1920 |
| Killing of 3 British Army Officers | Cork | Waterfall | 15 November 1920 |
| Capture and killing of 2 Auxiliaries | Cork | Emmet Place, Cork | [16] November 1920 |
| 3 IRA members killed in bomb explosion in Cork City | Cork | Princes Street, Cork | 23 November 1920 |
| Kidnap and killing of James and Frederick Blemens | Cork | Blackrock | [29] November 1920 |
| Dillons Cross Ambush | Cork | Dillons Cross, Cork | 11 December 1920 |
| Midleton Ambush | Cork | Midleton | 28 December 1920 |
| Dripsey Ambush | Cork | Dripsey | 28 January 1921 |
| Killing of Alfred Charles Reilly | Cork | Douglas | 9 February 1921 |
| Clonmult Ambush | Cork | Clonmult | 20 February 1921 |
| Coolavokig or Ballyvourney Ambush | Cork | Coolavokig | 25 February 1921 |
| British execution of 5 IRA prisoners | Cork | Cork Military Detention Barracks | 28 February 1921 |
| Killing of British soldiers in Montenotte | Cork | Montenotte | 28 February 1921 |
| Killing of Mary Lindsay and James Clarke | Cork | Leemount House | [14] March 1921 |
| Ballycannon, Clogheen | Cork | Ballycannon | 23 March 1921 |
| Killing of Major Geoffrey Compton Smith | Cork | Donoughmore | [28] April 1921 |
| O'Connell Street Ambush | Cork | OConnell Street, Cork | 14 May 1921 |
| Attacks on RIC in Midleton | Cork | Midleton | 14 May 1921 |
| British Army killings of IRA members and civilians in Midleton County Cork. | Cork | Midleton | 14-15 May 1921 |
| Youghal Mine Attack | Cork | Youghal | 31 May 1921 |
| Killing of 4 British soldiers at The Lough, Cork | Cork | The Lough, Cork | 10 July 1921 |
| Seizure of the 'Upnor' | Cork | Ballycotton | 29 March 1922 |
| Fighting at Passage West | Cork | Passage West | 10 August 1922 |
| Carrigaphooca Ambush | Cork | Carrigaphooca | 16 September 1922 |
| Engagement at Ballineen | Cork | Ballineen | 4 November 1922 |
1 and 2 Battalion cover Cork City with 16 companies and their combined strength was 2,287 on 11 July 1921 and 1,640 on 1 July 1922.
1 Battalion: Unit strength on 11 July 1921 was 1,164 all ranks, and the strength on 1 July 1922 was 830 all ranks.The eight companies of the 1 Battalion were all located in the city of Cork.
2 Battalion: Unit strength on 11 July, 1921 was 1,123 all ranks, and the strength on 1 July 1922 was 810 all ranks. (Note: no data provided for the strength of A Coy. of the 2 Bn. on the 1st critical date). The eight companies of the 2 Battalion were all located in the city of Cork.
3 Battalion: Unit strength on 11 July 1921 was 368 all ranks, and the strength on 1 July 1922 was 311 all ranks.The companies of the 3 Battalion were located as follows: Inniscarra, Kilumney, Waterfall, Aherla, Farran and Farnanes.
4 Battalion: Unit strength on 11 July 1921 was 1,221 all ranks, and the strength on 1 July 1922 was 333 all ranks.Note: there were nineteen companies in the 4 Battalion on 11 July 1921. By 1 July 1922 the Battalion had been divided to form the 10 Battalion and on that date eight companies remained to form the 4 Battalion. On 11 July 1921 the companies of the 4 Battalion were located as follows: Cobh, Youghal, Carrigtwohill, Knockraha, Castlemartyr & Dungourney & Mogelly, Midleton, Clonmult, Lisgoold, Leamlara, Ladysbridge, Killeagh, Inch, Cloyne, Aghada, Shanagarry, Ballycotton, Ballymacoda, Glounthaune, and Churchtown South.On 1 July 1922 the companies of the 4 Battalion were located as follows: Cobh, Midleton, Carrigtwohill, Knockraha, Castlemartyr & Dungourney & Mogelly, Lisgoold, Leamlara, and Glounthaune.
5 Battalion: Unit strength on 11 July 1921 was 386 all ranks, and the strength on 1 July 1922 was 321 all ranks.The companies of the 5 Battalion were located as follows: Whitechurch, Carrignavar, White’s Cross and Riverstown.
6 Battalion: Unit strength on 11 July 1921 was 763 all ranks, and the strength on 1 July 1922 was 439 all ranks.The companies of the 6 Battalion were located as follows: Courtbrack, Blarney, Donoughmore, Rylane, Inniscarra, Grenagh and Coachford.
7 Battalion: Unit strength on 11 July 1921 was 830 all ranks, and the strength on 1 July 1922 was 689 all ranks.The companies of the 7 Battalion were located as follows: Macroom, Clondrohid, Ballinagree, Rusheen, Canovee, Crookstown, Kilmurry, Toames and Kilmichael.
8 Battalion: Unit strength on 11 July 1921 was 653 all ranks, and the strength on 1 July 1922 was 630 all ranks.The companies of the 8 Battalion were located as follows: Ballyvoige, Ballymakeera, Coolea, Ballingeary and Inchigeela.
9 Battalion: Unit strength on 11 July 1921 was 698 all ranks, and the strength on 1 July 1922 was 372 all ranks.The companies of the 9 Battalion were located as follows: Rochestown, Monkstown, Passage West, Ringaskiddy, Carrigaline, Ballygarvan, Ballinhassig, Kinsale and Minane Bridge.
Note: by 1 July 1922 the Ballinhassig, Kinsale, and Minane Bridge companies had been posted to the 5 Bn. 3 Brigade, 1 Southern Division.
10 Battalion: Unit strength on 1 July 1922 was 205 all ranks.
Note: for the formation of the 10 Battalion, Cork No. 1 Brigade, see note on 4 Bn. above.On 1 July 1922 the companies of the 10 Battalion were located as follows: Aghada, Cloyne, Killeagh, Churchtown South, Ballycotton, Ladysbridge, Ballymacoda, Shanagarry, Inch and Youghal.
An Active Service Unit was effective on both critical dates. Personnel were attached to the A.S.U. from a number of the battalions of the Brigade (the 6, 7 and 10 battalions are specifically listed) and it would appear from the data available that the strength of the A.S.U. was in excess of 150 all ranks .