Short answers, pulled from the story.
Northern Ireland was created on the 3rd of May 1921, when the Government of Ireland Act 1920 came into force, partitioning the island of Ireland. It was established to accommodate the unionist majority in six north-eastern counties who wanted to remain part of the United Kingdom.
The Troubles killed 3,254 people and injured over 50,000 others. From 1969 to 2003, there were over 36,900 shooting incidents and over 16,200 bombings or attempted bombings across the conflict.
The Good Friday Agreement established a devolved power-sharing government, the Northern Ireland Assembly, requiring both unionist and nationalist parties to participate. It also led to paramilitary decommissioning, police reform, army withdrawal from the streets, and an amendment to the Irish Constitution removing its claim to sovereignty over the entire island.
Michelle O'Neill of Sinn Féin became the first ever Irish nationalist, republican, or Catholic to serve as First Minister of Northern Ireland. She was sworn in on the 3rd of February 2024.
At the 2021 census, 42.3% of the population identified as Roman Catholic and 37.3% as Protestant or other Christian. For the first time since Northern Ireland's creation, the census recorded more people from a Catholic background (45.7%) than from a Protestant background (43.5%).
Northern Ireland can sell goods to both the rest of the United Kingdom and to the European Union tariff-free, without customs declarations or non-tariff barriers. In 2021, this dual-market access supported £12.8 billion in sales to the UK and £5.2 billion in exports to the Republic of Ireland.