Peter Robinson was last night confirmed as the new DUP leader and vowed to oppose republicanism.
The decision was ratified by the 120 members of the party's executive, who unanimously backed the Stormont Finance Minister.
He will take over from Rev Ian Paisley who will retire in June as both DUP leader and Northern Ireland's First Minister.
Stormont Economy Minister Nigel Dodds was unanimously endorsed as the DUP's new deputy.
Mr Robinson said the post-Ian Paisley DUP will fight for its community's agenda and oppose republicanism at every turn as it has always done.
He called Mr Paisley "a legend".
"I made one request of the executive members tonight and that was, when some months or years down the road they want to make a judgment on the leadership of the Democratic Unionist Party that will follow Ian Paisley, that they compare it to (UUP leader Reg Empey) and all the others rather than comparing it to Ian Paisley. On that score I think we will come out ahead. But it is a very difficult, almost frightening prospect to follow the leadership of someone of such a mighty standing in the community, someone who is a legend within the unionist community.
"It is up to Nigel (Dodds) and I to give leadership along with our colleagues in the Assembly to the party and to the unionist community to make it clear we are fighting for the unionist agenda, we will oppose republicans at every possible opportunity we have.
He added: "The republican agenda is something we will resist."
