Arlene Foster of the Democratic Unionist Party formally became Northern Ireland's first minister on Monday, taking over from the retiring Peter Robinson ahead of regional elections in May.
Foster, 45, is the first woman and the youngest to hold the most senior political post in Northern Ireland, where power is shared between rival parties in a fragile administration set up to end conflict in the region.
The party she leads wants Northern Ireland to remain a part of the United Kingdom.
"I can think of no greater honour than to have the opportunity to serve my country and the people of Northern Ireland as their first minister," Foster said in her speech in the Northern Ireland Assembly.
A lawyer by profession, Foster recalled growing up in rural Fermanagh at the height of the conflict known as "The Troubles", in which her father was shot and she herself survived a bus bombing as a teenager.
She will work alongside long-serving Deputy First Minister Martin McGuinness of the opposing Sinn Fein party.
She vowed to work so that the assembly would no longer be "a watchword for arguing and bickering".
"I ask today that we find a new way of doing business, one that places a greater premium on consensus than on conflict," she said.
Foster takes power in the wake of a crisis in the assembly, often wracked by disagreement between unionists who support Northern Ireland's position within the United Kingdom, and republicans who want the province to be part of Ireland.
Her predecessor, 67-year-old Robinson, who had served as first minister since 2008, resigned in September due to a political crisis which was provoked by the murder of ex-Irish Republican Army (IRA) man Kevin McGuigan, who was shot dead in August in what was highly speculated to be a “punishment attack” after he was named as a suspect in the murder of his ex-colleague Gerard Jock Davison in May.
At the height of tensions between the two sides last year, Robinson and most of his DUP colleagues stepped aside from the assembly over concerns that the paramilitary Irish Republican Army still existed 17 years after a landmark 1998 peace deal ended decades of violence.
McGuigan’s murder was later linked to other former Provisional IRA members including Bobby Storey, the head of the Sinn Fein party’s northern branch. Storey was previously accused of being the head of the IRA’s intelligence in 2005.
A deal was later reached between the DUP, Sinn Fein and British and Irish governments to resolve problems that had deadlocked the administration.
The IRA, which was established in 1969 to fight for the cause of Irish republicanism, is listed as an unlawful terrorist organisation in both the UK and the Republic of Ireland. The group has carried out a number of bombings and assassinations since its founding, and is also known for its involvement in smuggling and robberies.
Although the group says it highly condemns sectarianism and sectarian attacks, its members having been involved in the killing of many Protestants and Catholics during the period of 1975-1976.
Tension inside the group led to splintering and when the Provisional IRA declared ceasefire with the UK government in 1997, the Real IRA came into being.
The Real IRA still believes that Northern Ireland should be united with the Republic of Ireland and continues to undertake violent attacks, generally targeting soldiers and police officers.