South Lakes MP Tim Farron has won the race to become the leader of the Liberal Democrats.
He secured just over 56% of the votes - beating former care minister Norman Lamb in a two-horse race.
Nearly 34,000 party members voted in the leadership election, with Mr Farron securing 19,137 votes and Mr Lamb 14,760.
After the result was announced, he thanked his supporters and said the job now was to "turn millions of liberals throughout the UK into Liberal Democrats".
Mr Lamb congratulated him on his victory, saying he will make a "fantastic" party leader who would champion social justice. He added Mr Farron would have his "full backing".
He has also been congratulated by former leader Nick Clegg on Twitter, who wrote: "Congratulations to new Lib Dem leader Tim Farron. It's a tough job but the best in politics. I know Tim will do us proud. #libdemfightback"
Mr Clegg said: "Tim Farron is a remarkable campaigner and a man of the utmost integrity and conviction.
"He is a natural communicator with a rare ability to inspire people and rally them to our cause.
"He knows how to win and I have no doubt he can pick the party up and get us fighting again."
Mr Farron announced in May that he was joining the race to succeed Mr Clegg after the party suffered a crushing defeat in May's General Election.
He now faces the challenge of turning the party round after it lost all but eight of its 57 Commons seats after five years in coalition government with the Conservatives.
After announcing his intention to stand, he reassured local people that his constituency is his home and will remain his top priority.
Mr Farron said that before making his decision to stand, he sought the views of his constituents - who he says overwhelmingly called on him to run for the leadership role.
He also received messages urging him to stand from members, councillors and parliamentarians across the UK. Among them were the leaders of the Welsh and Scottish Liberal Democrats, Kirsty Williams AM and Willie Rennie MSP, who described him as “a committed liberal, a brilliant communicator, an outstanding campaigner and an inspirational leader”.
Commenting in May on his decision to join the race, Mr Farron said: "I'm standing to be leader of the Liberal Democrats because I think Britain needs a political party who will stand up for the environment, human rights, equality and liberalism. I want to be the person who helps our party fightback and give Britain the liberal voice it needs.
“However Westmorland will always be my home and will remain my top priority. Nothing will distract me from that. When I was first elected I said that I would always be Westmorland’s man in Westminster and never the other way around. I will keep fighting for our hospital, to bring more investment to our area and to boost apprenticeships and jobs. These will always be the things I work on first, before anything else.”
Commenting, Barrow and Furness MP John Woodcock said: "Many congratulations to Tim on winning the leadership of his party. I know he will apply his characteristic energy and dedication to the national role and I wish him well for the future."
Mr Farron was re-elected as Westmorland & Lonsdale’s MP with more than 25,000 votes in May - almost 9,000 votes clear of his nearest rival for the seat.