LONDON — An Irish nationalist made history Saturday by becoming Northern Ireland’s first minister as the government returned to work after a two-year boycott by unionists.

Sinn Fein Vice President Michelle O’Neill was nominated as first minister in the government that under the terms of the 1998 Good Friday peace accord shares power between Northern Ireland’s two main communities — British unionists who want to stay in the U.K., and Irish nationalists who seek to unite with Ireland. Northern Ireland was established as a unionist, Protestant-majority part of the U.K. in 1921, following independence for the Republic of Ireland.

“The days of second-class citizenship are long gone. Today confirms that they are never coming back,” O’Neill said. “As an Irish republican, I pledge cooperation and genuine honest effort with those colleagues who are British, of a unionist tradition, and who cherish the Union. This is an assembly for all — Catholic, Protestant and dissenter.”

Neither side can govern without agreement from the other. Government business ground to a half over the past two years after the Democratic Unionist Party walked out to protest trade issues related to Brexit.

O’Neill will share power with deputy first minister Emma Little-Pengelly from the DUP. The two will be equals, but O’Neill, whose party captured more seats in the Northern Ireland Assembly in the 2022 elections, will hold the more prestigious title.

Former DUP leader Edwin Poots was elected as speaker of the chamber.

O’Neill, 47, was elected to the Stormont Assembly in 2007 and comes from a family of Irish republicans. Her party, Sinn Fein, was affiliated with the militant Irish Republican Army during the Troubles, a period of about 30 years of violent conflict over the future of Northern Ireland which ended with the Good Friday Agreement.

Former Sinn Fein president Gerry Adams, who helped broker the historic peace agreement, was in the gallery at the assembly to see O’Neill’s nomination.

Sinn Fein Vice President Michelle O’Neill walks through Stormont Parliament Buildings in Belfast, Northern Ireland, Saturday, Feb. 3, 2024. O’Neill is poised to make history by becoming the first Irish nationalist leader of Northern Ireland as the government returned to work after a two-year boycott by unionists.(AP Photo/Peter Morrison)

The return to government came exactly two years after a DUP boycott over a dispute about trade restrictions for goods coming into Northern Ireland from Great Britain. Northern Ireland’s 1.9 million people were left without a functioning administration as the cost of living soared and public services were strained.

An open border between the north and the republic was a key pillar of the peace process that ended the Troubles, so checks were imposed instead between Northern Ireland and the rest of the U.K.

An agreement a year ago between the U.K. and the EU, known as the Windsor Framework, eased customs checks and other hurdles but didn’t go far enough for the DUP, which continued its boycott.

The U.K. government this week agreed to new changes that would eliminate routine checks and paperwork for most goods entering Northern Ireland, although some checks will remain for illegal goods or disease prevention.

Jeffrey Donaldson, leader of the DUP, speaks to the media at Stormont Parliament Buildings in Belfast, Northern Ireland, Saturday, Feb. 3, 2024. Sinn Fein vice president Michelle O’Neill is set to become the first nationalist first minister following a two-year political collapse. Members of the Legislative Assembly (MLAs) will gather at Parliament Buildings at Stormont on Saturday for a sitting where ministers will be appointed to a powersharing executive, bringing an end to the impasse.(AP Photo/Peter Morrison)

The new changes included legislation “affirming Northern Ireland’s constitutional status” as part of the U.K. and gives local politicians “democratic oversight” of any future EU laws that might apply to Northern Ireland.

The U.K. government also agreed to give Northern Ireland more than 3 billion pounds ($3.8 billion) for its battered public services once the Belfast government is back up and running.

“I believe that my party has delivered what many said we couldn’t,” DUP leader Jeffrey Donaldson said outside the assembly chamber in Stormont. “We have brought about change that many said was not possible, and I believe that today is a good day for Northern Ireland, a day when once again our place in the United Kingdom and its internal market is respected and protected in our law and restored for all our people to enjoy the benefits of our membership of the union.”