Scottish Conservatives have elected newcomer Ruth Davidson as their new leader.
The 32-year-old only entered the Scottish Parliament in May as a regional MSP for Glasgow.
Ms Davidson replaces Annabel Goldie, who announced her intention to step down days after losing two seats in the Scottish election.
Prime Minister David Cameron welcomed his party's new leader in Scotland.
He said: "I am delighted to congratulate Ruth on winning this leadership election and look forward to working with her to strengthen the Union and build a better future for Scotland."
Ms Davidson is the first overall leader of the party in Scotland, rather than just the Holyrood group. She won the election in three rounds, leading at each stage.
Following the declaration at a hotel in Edinburgh today, she said: "With the radical, generational change that I represent, this is a unique opportunity for us to rebuild the party and to once again become a powerful, meaningful and relevant force in Scottish politics and in Scottish life.
"Our loyal and hard-working members in the associations and constituencies are the lifeblood of our party. But there has been a failure to fully involve them both in policy development and party management and strategy. That will now change."
She continued: "The Scottish Conservative and Unionist Party is very much alive and kicking. That has been very clear in the exhilarating debate we have had during this campaign.
"It is now up to all of us to build on that momentum and drive the party forward to a new and exciting age of success."
Turning to the forthcoming referendum on Scottish independence, she said: "We in the Scottish Conservatives have a duty as well as an opportunity to be the party that stands up for Scotland as a vital component of the Union.
"We must not allow the SNP to tear up that right. Scotland is not being served if politicians behave like rabbits caught in the headlights of Salmond's separatist steamroller. We must have the courage and conviction to stop him in his tracks by always presenting and promoting the positive case for the Union.
"Of course, a union that does not adapt and evolve will inevitably become stale, so it is essential that we adjust, refresh and revitalise the partnership. But strong, enduring marriages do not end in divorce, they continue to provide safety, security and mutual benefit and respect. That will always be worth fighting for.
"This is a time of generational change for the Scottish Conservatives, a party for all, regardless of age and of background. I want everyone to feel that they have a place, a role and a voice that can and should be heard. I want to engage the whole party from the grassroots up and to extend that conversation with the electorate at large.
"The hard work starts here. Today is the first day of a new and bright future of the Scottish Conservative and Unionist Party."
Ms Davidson, a former BBC journalist, was inspired to enter frontline politics by David Cameron's call for fresh faces in the wake of the MPs expenses scandal.
She fought the Glasgow North East by-election in 2009 - a seat the party was never likely to win - and worked for Miss Goldie before gaining a seat in Holyrood as the only Tory MSP in the Glasgow region.
Ms Davidson, who is openly gay, is a member of the Church of Scotland and counts kickboxing among her hobbies.
Ms Davidson was challenged for the position by Murdo Fraser, Jackson Carlaw and Margaret Mitchell.
Mr Fraser ran on a pledge to scrap the "tainted" Conservative brand and start a new centre-right party - a move that split senior figures and prompted Ms Davidson to announced she would run against him.
Following the result, Mr Fraser said: "Clearly I'm disappointed that I was not able to persuade more of our members that my vision for the future is the correct one.
"But I congratulate Ruth Davidson on her victory, and she will have my full support, as she tries to take the party forward.
"I think the bold and radical proposal that I had - to create a new centre-right party for Scotland, to replace the Conservatives - was a leap too far for the majority of our members.
"A sizeable minority, 45%, voted for my proposal but it was not enough."
He secured 2,096 first preference votes against Ms Davidson's 2,278.
David Mundell, the only Tory MP in Scotland, supported Ms Davidson's bid and said: "Ruth embodies the radical, generational change that the party needs to rebuild and reclaim its place at the heart of Scottish politics and Scottish life.
"I look forward to working closely with her and I am certain she will be a first-class leader for the whole party."
Ms Mitchell, a late entry to the race, was knocked out with 472 votes in the first round.
Mr Carlaw, who was taken to hospital with appendicitis during the campaign, was considered a strong challenger for the top job but finished third with 830 first-choice votes.
There were 5,676 votes cast in a turnout of 63.4%.