Violence has flared for a week in Northern Ireland, stoked by tensions over Britain’s departure from the European Union, reviving memories of three decades of sectarian conflict.
Here are five things to know about the province, which shares a border with the Republic of Ireland, still a member of the EU.
Under the British crown
The island of Ireland was incorporated into Britain in 1801 after nearly seven centuries of to-and-fro struggles with the English crown.
Three years after a failed bloody rebellion in Dublin, a guerrilla war for independence is launched in 1919 by a Roman Catholic group called the Irish Republican Army (IRA).
It resulted in the island being split in 1921 into a Catholic-majority Irish Free State in the south and a smaller Protestant-majority Northern Ireland.
The north remained within the United Kingdom, while the south cuts ties with the British crown completely when it became a republic in 1948.
Today Northern Ireland’s population of 1.9 million is three percent of the UK total.
Anger among minority Catholics in Northern Ireland over discrimination erupted into riots in 1968 and the British army was sent in.
It was the start of three decades of unrest called “The Troubles,” which would claim 3,500 lives, marked by bombings and shootings by rival Catholic IRA and Protestant groups.
One of the worst episodes was “Bloody Sunday” in January 1972, when British soldiers opened fire on a peaceful civil rights march in Londonderry, killing 14 Catholics.
Two months later London dissolved the Protestant-dominated Northern Ireland parliament and imposed direct rule.
There were hopes the conflict would be ended by a historic power-sharing government between Protestants and Catholics in 1974 under the Sunningdale Agreement.
But this collapsed within months after a general strike and street revolt led by hardline Protestant cleric the Reverend Ian Paisley –- the founder of the Democratic Unionist Party — and loyalist paramilitaries.
The Good Friday Agreement, signed on April 10, 1998 that ended the Troubles was famously described as “Sunningdale for slow learners.”
The Good Friday Agreement led to a power-sharing between republican and unionist parties to run the province’s semi-autonomous institutions.
The two largest groups are the Protestant Democratic Unionist Party (DUP), and the IRA’s republican political wing, Sinn Fein.
The power-sharing executive broke down in 2017, after a row over a fuel subsidy scandal.
With the two sides at loggerheads, Northern Ireland’s affairs were managed from London.
In the UK’s 2019 elections the province elected more Republican MPs in favor of reunification with the south than unionists of the DUP, who want to remain in the UK.
The Northern Ireland Assembly resumed in January 2020.
Brexit and borders
Northern Ireland shares an open 500-kilometer (310-mile) border with Ireland.
The Good Friday agreement enabled unionists and nationalists to coexist by blurring the status of the region within the EU.
But Britain’s 2016 vote to quit the bloc revived the need for border checks on trade, potentially undermining the pact, and feeding into tensions that have flared over the past week on the streets of Belfast and elsewhere.
A special “protocol” was agreed that shifted controls away from the Irish land border to ports trading with the UK mainland.
This took effect on January 1, prompting many unionists to accuse London of betrayal and diluting Northern Ireland’s status in the UK.
Northern Ireland is one of the poorest parts of the UK.
Its heavily-subsidized economy was previously based on public services and heavy industry, with the Titanic built in Belfast’s shipyards.
The EU has contributed 1.3 billion euros ($1.4 billion) to Northern Ireland since 1995 for economic development aimed at consolidating peace.
Thawing conservative laws
Northern Ireland has until recently been the only part of the UK to not allow same-sex marriages, a position defended by the ultra-conservative DUP.
In October 2020 Westminster forced through laws to liberalize abortion laws and legalize same-sex marriage.