The Christmas Raid was an attack by the Irish Republican Army (IRA) against the Irish Army and the Phoenix Park Magazine Fort—Ireland's largest munitions dump. The attack resulted in the capture of the munitions dump by the IRA and the seizure of a huge quantity of weapons.
The raid took place on 23 December 1939 and was immediately prior to the passing of the Emergency Powers Act in Ireland. Although the operation was initially successful, two of the raiders were captured shortly after the raid, and in the following days, most of the stolen military equipment was recovered, and several IRA volunteers were arrested.
The Dublin Magazine Fort was built in 1735. The fort is in the west of the city, north of the River Liffey within Phoenix Park. The building is located in the south-eastern part of the park, close by a wooded ridge, and has a commanding view of the surrounding area. During the British occupation the Fort had been seen as a symbol of the occupation, but by 1939 its purpose was to house the Irish Army's stocks of arms and ammunition.
The IRA was still involved with the Sabotage Campaign at the time of the raid, with a lot of units either interned, on the run, in Britain, or recently deported from Britain. A number of members of the Army Council were also on the run, trying to evade capture by the Garda Síochána (Irish police). The stated reason for a raid on the Fort being ordered was that although the IRA had many Thompson submachine guns (imported with the help of Clan na Gael over the preceding decade), the .45 ACP ammunition used in these guns was not easily available in Europe. It so happened that the Irish Army also used the Thompson and had large supplies of ammunition. Permission was sought to steal ammunition, either from the Magazine Fort or nearby Islandbridge Barracks. Acting Chief of Staff in Seán Russell's absence, Stephen Hayes, gave the order.