system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Ireland, the IRA, and overall what the fuck happened...

Also why bombs and terrorist tactics. I've looked up this subject before but was confused was not really able to grasp the why?
gpt
Ireland fell under English control in the 1500's, and remained so despite frequent revolts, until the early 1900's.

Religion was a large factor, as England was Anglican, while Ireland was Catholic.  To try to gain better control, in the 1600 and 1700's, English citizen were encourage to colonize Ireland, particularly in the north.  The hope was that an English population in Ireland would dilute the Irish influence and make it easier to control.

It didn't really work out that way, it just put Anglican English and Catholic Irish closer together so it was easier to fight.  After World War I, England (now the UK) finally decided to let Ireland become an independent country.  But because there were a lot of English living in the north, they divided it, with the south becoming its own nation, and the north remaining part of the UK.

*This* is what everyone is fighting over.  Over the centuries, there were lots of English and Irish living in Northern Ireland, all mixed together.  The Irish think it should be part of Ireland proper, while the English think it should remain with England.  

The IRA is the organization that wants Ireland to be unified, and the Ulster Unionist want to stay with England.  Both group have resorted to illegal violence in the past.