On formation of the IRA in 1919-20, the existing Irish Volunteer Companies of the Belfast Battalion simply became A and B Company of the IRA’s Belfast Battalion, with a C Company and D Company added in early 1919. It isn’t clear now whether each Company had strict catchment areas. The city’s IRA units were then re-organised, beginning in September 1920, when the companies were divided into a 1st and 2nd Battalion and by March 1921, officers and experienced members from the four existing Companies had been used to staff Companies in each of the two Battalions, which now formed part of the 1st (Belfast) Brigade of the 3rd Northern Division. The 1st Battalion had Companies A to E and an Engineering Company. While C Company was centred on Carrickhill, the other Companies covered the Falls Road (again demarcation lines appear vague). The Companies of the 2nd Battalion each had a geographic focus, with A Company in Ardoyne and the Bone, B Company in Ballymacarrett, C Company in the Markets and D Company in North Queen Street. By April 1921, Na Fianna and Cumann na mBán structures were been aligned onto the IRA’s Divisional command structure.
In August 1921, two additional Battalions were created under the 1st (Belfast) Brigade, as 3rd and 4th Battalion and the Engineering Company of 1st Battalion effectively became a distinct Engineering Battalion in its own right. The new Battalions were created from the existing companies, such as the 3rd Battalion’s B Company which was based on the New Lodge Road. Many of those who joined the 3rd and 4th Battalions enlisted after the Truce and were derided as Trucileers by pre-July 1921 veterans.
The status of the 1st Belfast Brigade from 1922 is complex. As it mounted an offensive against the northern government from May 1922, it continued to remain in contact with both the Army Executive and Free State government until formal liaison with Headquarters ended around October 1922. It also appears that most of the 2nd Battalion and all the 3rd and 4th Battalion Companies did not recognise the authority of the Free State government by July 1922.
The 1st (Belfast) Brigade command structures were, effectively, autonomous until the end of 1924 when the re-interment of Joe McKelvey’s remains in Belfast became the catalyst for the Belfast command to re-establish formal links to the IRA’s GHQ in Dublin. It was apparent, by this time, that the obsolete Divisional structure that had been put in place in 1920 needed to be replaced with something more suitable for the post-Civil War IRA.
The newly created Belfast Battalion had a staff with elected representatives of the Falls, Ardoyne, Bone, Carrick Hill, North Queen Street, Greencastle, Markets and Ballymacarret. It reported directly to GHQ in Dublin through a Communications Officer, in the absence of a middle-ranking regional command structure although it is often formally referred to as Ulster No. 1 Divisional Area. The Belfast Battalion was now organised into two Companies, both located on the Falls Road and an independent unit that covered Ardoyne, the Bone and North Queen Street. Volunteers from Greencastle joined the independent unit, while those from the Markets and Ballymacarret joined the Falls Road unit that covered the city centre.
Following the De Valera split, there was a further consolidation with Cumann na mBán, the IRA, Na Fianna and Sinn Féin that took place before the middle of 1928. The Belfast Battalion now undertook an expansion programme including a renewed focus on Na Fianna as a source of recruits. District-based Companies were formally re-established beginning with Ballymacarrett. In the short term, there was a decline in strength between 1926 and 1930, from 242 to 177. Ulster No. 1 Area now had Companies A to G, with A Company covering North Queen Street, Carrickhill and the Docks, B Company covering Ballymacarrett and the Markets, C Company based in Ardoyne and the Bone, D Company on the Falls and F Company centred on the Pound. The other companies (E and G) covered from Clonard out to the Whiterock, Hannahstown and Andersonstown. The throughput of recruits from Na Fianna saw the Belfast IRA Companies expand in size to 564 members by 1932.
The Belfast IRA retained this structure through the 1930s, reporting directly to GHQ, until the beginning of the English Campaign in 1939, at which time regional commands were created as a response to pressures restricting the ability of GHQ to exercise control on activity in other districts. This was particularly the case in the north, where a Northern Command that was set up and then re-organised under Charlie McGlade in the summer of 1939 to include Donegal. The Northern Command included representatives from each local IRA unit, with the likes of the officer commanding (O/C) of the Belfast IRA concurrently holding a staff position on Northern Command (often the Adjutant of the Northern Command was O/C Belfast). By 1941, the internees and sentenced prisoners in the jails in Belfast, the Al Rawdah, Derry and Armagh also reported directly to the Northern Command via the Adjutant, with the internees in D wing in Belfast organised as Battalion No. 1 and the sentenced prisoners as Battalion No. 2.
A H Company was added secretly to the Belfast Battalion during 1941, which was a special section of mainly Protestant IRA volunteers which carried out particular tasks and roles. By the start of 1942, arrests and internment had led to a complete re-organisation of the Battalion back into four Companies (once again labelled A-D). For the remainder of the mid-1940s, these survived in a skeletal form and the Northern Command and GHQ both became inactive due to arrests and defections.
By the time the internees and sentenced prisoners had been released, the Belfast Battalion was effectively reduced to a single company. This remained the case until 1956 when, as part of the pre-amble to the Border Campaign, the Belfast Battalion was re-organised into two Companies. One was made up of veterans and others who were likely to be known to the RUC. The other was made up of younger, unknown Volunteers who were unknown to the RUC (and possibly also an informer who was believed to be active among the Belfast Battalion staff). Despite the widespread belief that Belfast was to play no part in the Border Campaign, Paddy Doyle, the Belfast Battalion O/C was fully aware of plans and operations to be carried out in Belfast (such as cutting the cable to Britain on the night of December 11th /12th 1956). As he had kept all the operational details to himself, the Belfast Battalion wasn’t able to re-organise in time after Doyle’s arrest to carry out the action.
The Belfast IRA was decimated by internment in 1956 and 1957 and was rebuilt by Billy McKee after his release. By 1961 the concept of a Northern Command had arisen again but not adopted. The Belfast IRA was to remain small until the changes that occurred in 1969-70 when, following internal upheavals, it broke connection with the then GHQ staff and leadership.