Ireland’s place in the British Empire is a long and complicated affair, but in short, the Tutors were the first to properly conquer Ireland, and start replacing its relatively more native/Gaelicized upper classes with Protestants and people who were English in culture, and remained that way. And particularly after the Williamite Wars, Ireland became infamously and continuously rebellious against English Rule. For many years this came in the form of supporting alternate claimants to the English Throne, but by around the late 1700’s, with the American and French Revolutions, the revolts and rebellion were now for a more or fully independent Ireland. And all throughout, sectarian tensions, and the sectarian-isation of these revolts rose, as they became ever more identified as Catholic and and Anti-Protestant (Anti-English) affairs.

For the Troubles of the late 20th Century, the most important revolt was the Easter Rising of 1916. If you ever listen to any “Rebel Songs”  the events of 1916 are mentioned or referenced in many. To very much simplify, a group called the Irish Republican Brotherhood organized a plot to take Dublin and establish an Independent Ireland while the British were occupied with WWI. Three militia groups, the Irish Volunteers, Irish Citizen Army, and the Cumann na mBan (The Women’s Council), sent troops to Dublin. They managed to take a few strategic buildings, but the British Army responded quickly and in force. The fighting lasted for six days and the British shelled the city, and were not the most discriminating, resulting the majority of casualties actually being civilian. But the British did win, and the rebels surrendered. After this, the British executed 16 leaders of this revolt. Of course, this really only served to make them martyrs.

The Rising would lead rather directly to the outbreak of the Irish War of Independence in the early 1920’s, which marked a significant victory for Ireland, though it was not yet fully independent of England. By the Anglo-Irish Treaty, the Irish Free State was established and was made a Dominion like Canada, Australia, etc, giving this state a massive amount of internal independence. It was also with this Treaty that Northern Ireland was created, due to the Protestant (especially Anglican) majority there who opposed Irish Independence, and wished to remain part of England. This was of course, rather unsatisfactory for many, and so a Civil War was fought for a few years over whether to take this deal and get full independence later, or keep fighting for true independence now. However, the Pro-Treaty forces won out, and so the Free State remained and sought full independence through political and diplomatic means. A major constitutional change came in 1937 that meant the country was effectively truly independent in its operation, and changed the name to the Republic of Ireland, as it is today. Then in 1948-9, Ireland’s commonwealth status was finally terminated and it became truly fully independent of England (though the Crown of Ireland Act of 1542 wasn’t formally repealed until 1962, though it was already very defunct by that point).

Meanwhile, in Northern Ireland, there were still Catholic Communities. Indeed, a couple of the counties in Northern Ireland had Catholic majorities, and the city of Derry did as well. Over all, Catholics were about 1/3 of the Population, the rest being Protestants, and those being mostly Anglican (but with minority Methodist and Presbyterian communities as well). However, things were subtly rigged against the Catholics by the government. The RUC, the police, were overwhelmingly Protestant, with very, very, few Catholics. Most notably, there was intense gerrymandering to give Catholics less votes then they should have otherwise gotten. Even more, the right to vote was tied to property ownership and specifically paying ownership rates. People in rented or public housing were not allowed to vote at all, and having multiple homes would get you more votes (up to 6, they also had to be in different wards). Unsurprisingly, Protestants were more likely to own homes then Catholics were at this time. And still on top of this, Catholics were discriminated against in the housing market. Houses were in short supply at that time, and many were old (around a century) and in need of renovation, so instead of being merely bought they were allocated to those in search of housing, but the authorities in charge of this were of course Unionist, and so Protestants were always given favor inspite of all other factors. All of this together meant that even in places with Catholic Majorities, more Protestant politicians would be elected than Catholic ones. Whats even more, Northern Ireland was not the most hospitable to Irish culture. It was outright illegal to fly the tricolour flag of the Republic, Irish history was deprioritized in education (state schools were often quite Protestant, while Catholic families often sent their kids to private Catholic Schools), and the party of Republicanism, Sinn Féin (and still one of the most popular parties in both Irelands today), was banned.

All in all I think you can see how Catholics had become something of second-class citizens. However, back in 1947, there had been an Education Act that made education more accessible for everyone, and so, when the 1960’s came around, a generation of better educated Irish young adults were on the scene. All of this led to a Civil Rights movement for Catholics in Northern Ireland, but this is also where the Troubles began. On October 5th, 1968, two Catholic Civil Rights organizations, the NICRA and the DHAC, planned to hold a march in Derry, but the government banned this protest. Of course, they went out anyway, and the RUC was sent out and violently drove them off the streets. The event even happed to be filmed by ROI news channel RTÉ.

And this incident, is what, finally, started the Troubles. From here, more riots would ensue, like the multi-day rioting of the Battle of the Bogside, and the IRA would quickly get involved as a terrorist organization, to “protect” Catholics in Northern Ireland, and as the violence increased, the British Army was sent in, and from there the conflict escalated.