The conflict in the majority unionist northern counties was very different to that in the south, where the IRA enjoyed widespread support. Most areas, except Belfast and Monaghan, had no IRA brigade structure. IRA attacks on police targets led to sectarian reprisals on Catholics, whom the IRA were unable to protect. Violence in the northern counties increased after Partition in mid-1921, and the Northern IRA collapsed during the Civil War when left without support from the south.
