The IRA in west Mayo was relatively quiet until January 1921, when Michael Kilroy, described as, "a puritanical and ascetic blacksmith"[4] took over command of the Brigade after Tom Derrig was arrested by the Royal Irish Constabulary.

On 6 May they suffered a reverse at Islandeady, when a police patrol came upon the IRA men cutting a road; three volunteers were killed and two captured.

However, the police tracked them there and, in another exchange of fire, another IRA man was killed, Jim Brown from Newport, along with one RIC Constable and a Black and Tan.

At the funerals of those killed, in Castlebar, the authorities allowed only close family to attend and forbade the draping of the Irish tricolour over the coffins.

Kilroy's column managed to get some revenge for the setback at Kilmeena the following month (3 June) in an action at Carrowkennedy, where they killed eight policemen and captured 16.