The Prime Minister has hailed a “new dawn” as the UK officially leaves the European Union.
The UK will now enter into a standstill transition period with Brussels, meaning trade and travel arrangements will stay the same for the rest of this year.
Johnson hopes to rapidly negotiate a trade deal with the EU that would take effect in 2021, once the transition is over.
Ahead of Brexit, the PM said in a video message: “When I look at the potential of this country waiting to be unleashed, I know that we can turn this opportunity into a stunning success.”
But it comes as First Minister Nicola Sturgeon pressed her case for a second independence referendum in an announcement earlier in the day in Edinburgh.
She said Brexit was “pivotal moment” of “real and profound sadness… tinged with anger” after Scots voted 62% to Remain in 2016.
The SNP leader stated that “the UK that Scotland voted to remain part of in 2014 – a UK inside the EU – will no longer be a reality” as she refused to rule out holding a “consultative” independent ballot without Westminster’s authorisation.
Pro-Remain candlelit vigils have been taking place across Scotland as part of a series of events marking Brexit day.
The Leave a Light On gatherings were held in Aberdeen, Dundee, Glasgow, Stirling and a number of other places as protesters sent a message to the EU not to forget Scotland.
In Glasgow, pro-EU campaigners gathered at the Donald Dewar statue on Buchanan Street, joined by SNP MPs Alison Thewliss, Alyn Smith, Philippa Whitford and Kirsten Oswald, along with Scottish Green co-leader Patrick Harvie.
In London, pro-Brexit supporters celebrated at a Leave Means Leave rally in Parliament Square with Remain-supporting counter-demonstrators also out in Westminster.
Downing Street was illuminated by a red light and blue light show, along with the Treasury, the Ministry of Defence, the Ministry of Justice, HMRC, the Cabinet Office plus the Offices of Scotland and Wales.
A countdown clock was projected onto Downing Street buildings to mark the exact moment the UK left the EU at 11pm.
In contrast, two Scottish Government buildings, St Andrew’s House and Victoria Quay, were lit in the blue and yellow colours of the European flag.
Europe’s flag will continue to fly at St Andrew’s House and Victoria Quay, as well as at Scotland House in Brussels and at the Scottish Parliament, after MSPs overturned a decision to take it down.