Nigel Farage has described Britain's departure from the EU as "the greatest moment in the modern history of our great nation".
The Brexit Party leader’s remarks came as addressed his fellow Brexiteers gathered to mark the historic moment in Parliament Square on Friday night.
He addressed the crowd from a stage at his Leaves Means Leave party before the 20 second countdown to 11pm, when the UK officially left the bloc.
"This is something that I fought for - for 27 years and something that many thousands of you gave your time and money for,” Mr Farage said.
"We faced an established that didn't even want to listen to us. An establishment that never wanted that referendum to take place. An establishment that tried for three and a half years to frustrate the will of the greatest democratic mandate ever seen."
He added: "The people have beaten the establishment. The real winner tonight is democracy.
"Let us celebrate tonight as we have never done before. This is the greatest moment in the modern history of our great nation."
Boris Johnson hailed as the moment as the “beginning of a new era”.
“For many people this is an astonishing moment of hope, a moment they thought would never come,” the Prime Minister said before the countdown.
After years of bitter wrangling since the 2016 referendum, Mr Johnson said his job was now to "bring this country together".
There will only be minimal changes as the deal negotiated by the UK and EU keeps Britain aligned with EU rules for the rest of the year.
But attention has already turned to the next set of talks aimed at securing the future relationship which will apply from January 1, 2021.
And Mr Johnson has been clear he also wants to strike deals with countries around the world - notably Donald Trump's USA.
Brussels is pessimistic about the 11-month timetable for reaching a deal and made clear that Britain will have to accept worse terms and conditions for trade than if it were still a member of the EU.
European Commission president Ursula von der Leyen said: "We want to have the best possible relationship with the United Kingdom, but it will never be as good as membership."
