Sir Jeffrey Donaldson: From personal tragedy in the Troubles to £1bn deal with Theresa May - who is the new DUP leader?

A former soldier in the Ulster Defence Regiment, the Troubles had a profound effect on Sir Jeffrey Donaldson but he rarely speaks of his family's loss.

His cousins Samuel and Alexander Donaldson - one of the brothers a police constable and the other a chief inspector - were murdered in separate IRA bombings.

Sir Jeffrey, 58, has been an MP for 24 years and the DUP's Westminster leader since Nigel Dodds lost his seat in the last election.

He is the second former member of the Ulster Unionist Party to become leader of the rival Democratic Unionist Party, founded by Rev Ian Paisley.

Sir Jeffrey and Arlene Foster, who was ousted as DUP leader in April, both defected in protest when the UUP signed the Good Friday Agreement.

He will need the skill with which he negotiated the £1bn deal with the Tories after the 2017 election if he is to keep power-sharing afloat at Stormont.

He was the DUP's chief whip when Theresa May failed to secure a Commons majority and the party found itself holding the balance of power.

Sir Jeffrey, who was knighted by the Queen in 2016, has previously said he would resign his Westminster seat to become first minister at Stormont.

Speaking after submitting his nomination papers for leadership, he pledged to make the abolition of the Irish Sea border his priority if appointed.

He said: "Now, more than ever, we need to unite in the face of the threats posed to Northern Ireland by the Protocol.

"Make no mistake, this is the number one issue facing our country, our people and our place within the United Kingdom.

"If elected, I will ensure that the government doesn't just listen, but recognises the need to take decisive action to deal quickly with the Protocol."

Subscribe to the All Out Politics podcast on Apple Podcasts, Google Podcasts, Spotify, Spreaker

"A failure to act will undoubtedly have consequences for the stability of our political institutions and the prosperity of our economy," he added.

"We need to unite as a party and take heed of the challenges that Northern Ireland faces."

He is the DUP's fifth leader in its 50-year history, succeeding Rev Ian Paisley, Peter Robinson, Arlene Foster and Edwin Poots.