Arlene Foster appointed first minister

She became the first woman to hold to one of the two leading posts in the power-sharing Executive.

The 45-year-old, from Co Fermanagh, has already replaced Mr Robinson as leader of the DUP.

Mr Robinson, 67, announced his intention to retire from frontline politics last November, days after signing a political deal with Sinn Fein and the British and Irish governments to stabilise the administration.

The transition of power has been smooth, with Mrs Foster facing no challengers within the DUP.

The Fermanagh and South Tyrone Assembly member, a married mother-of-three who defected to the DUP from the Ulster Unionists in 2004, will assume office alongside long-serving Sinn Fein Deputy First Minister Martin McGuinness.

As First and Deputy First Ministers are required to be appointed together, Mr McGuinness will be re-nominated to his role as part of Monday’s Assembly procedures.

Mrs Foster has extensive experience serving in the Stormont Executive, having held three ministerial portfolios and twice having filled in as temporary first minister.

The new leader’s first electoral test will come in May with the Assembly election.

The challenge for the DUP will be to retain its position as Northern Ireland’s largest party and thus its right to hold the post of First Minister.

If the DUP were to lose enough seats to unionist rivals, there is the chance a strong performance from Sinn Fein could see the republican party top the poll.

While the posts of First Minister and Deputy First Minister are co-equal and hold the same authority, Mrs Foster will nevertheless be determined to avoid the symbolism of swapping job titles with Mr McGuinness.

Peter Robinson steps down saying he is confident that devolution is secure for years to come