Wednesday marked a historic day as British Prime Minister Theresa May announced that Article 50 of the Lisbon Treaty had been signed, commencing the formal process for Britain to withdraw from the European Union.
Britain is the first country in the EU in more than 60 years to seek a divorce from the union.
In her address to Parliament on Wednesday, May said, "There is no turning back." Outside Parliament, mixed reactions marked the day as pro-EU protesters gathered and the world tries to figure out what the move will mean for the future of Britain.
Scroll through to see more scenes from the day.
May signs the official letter to European Council President Donald Tusk invoking Article 50 and marking the United Kingdom's intention to leave the EU on March 28, 2017, in London.
Anti-Brexit protesters, one wearing a giant Theresa May head, hold placards outside Parliament on the day May announced that she has triggered the process by which Britain will leave the European Union.
Britain's ambassador to the EU, Tim Barrow (L), shakes hands with Tusk after handing him the British prime minister's formal notice of the UK's intention to leave the EU under Article 50 of the Lisbon Treaty in Brussels.
An arrangement of newspapers pictured in London on March 29, 2017, as an illustration, shows the front pages of the UK daily newspapers.
A pro-European Union (EU) supporter stands draped in an EU flag near the Houses of Parliament in central London on March 29, 2017.
Demonstrators from pro-EU group Open Britain protest outside of the Houses of Parliament.
European Council President Donald Tusk holds a news conference after receiving British Prime Minister Theresa May's Brexit letter in notice of the UK's intention to leave the bloc under Article 50 of the EU's Lisbon Treaty to EU Council President Donald Tusk in Brussels, Belgium, March 29, 2017.
A pro-EU protester dressed as Prime Minister Theresa May takes part in a demonstration near Parliament.
Former leader of the anti-EU U.K. Independence Party (UKIP) Nigel Farage drinks outside a pub in Westminster in London on March 29, 2017.
A pro-remain protester holds up an EU flag with one of the stars symbolically cut out in front of the Houses of Parliament shortly after British Prime Minister Theresa May announced to the House of Commons that Article 50 had been triggered in London on March 29, 2017.